家中富收藏，幼年即接触大量古今字画。十四岁开始习画，稍后，又入当时海上著名书法画家、鉴赏家吴湖帆先生之门，书画与鉴赏能力日进，年不及三十，即以擅鉴古书画闻名于江南。一九三七年协助上海市博物馆办理“上海市文献展览”中的古书画征集、检选、陈列之工作，受叶恭绰先生之托撰写《古书画提要目录》。
著有《古书画鉴定概论》、《古书画伪讹考辨》、《古书画过眼要录》、《重编清宫旧藏书画目》等。晚年鉴考之余，重拾画笔，创作山水，笔致秀润，意趣幽深。擅古典诗词。历任故宫博物院研究员。
2012年2月23日上午8时38分逝世。

徐邦达，1911年生于上海。父徐尧臣，绸缎商人，但喜收藏，故家中收藏赡富，徐邦达自幼即深受薰陶。
十四岁开始习画，从苏州老画师李涛（醉石）学习绘画，从赵时棢（叔孺）学习古书画鉴定知识。稍后，又入当时海上著名书法画家、鉴赏家吴湖帆先生之门。
1937年协助上海市博物馆办理“上海市文献展览”中的古书画征集、检选、陈列之工作，受叶恭绰先生之托撰写《古书画提要目录》。
1946年入中华美术会，任上海市分会理事，同时受聘为重建上海市美术馆的筹委会顾问 。
1947年曾在上海中国画苑举办个人画展。
1949年，被骋为上海市文管会顾问。
1950年，经国家文物局郑振铎局长推荐，调至文物局文物处工作。
1953年后，转至故宫博物院从事古代书画鉴定研究工作。
1953年，以各地征集和收购到的3500幅珍贵书画作品为基础，重建故宫博物院书画馆。
1978年始，应国家文物局之约参加全国书画文物鉴定专家组，为全国各地博物馆鉴定国家珍贵文物，并承担了培养后学之责。
历时八年，成《中国古代书画图目》多卷。
1980年代以后，多次出访美国、澳大利亚、加拿大等国，考察海外流失中国书画并与国外专家进行学术交流，取得多项学术成果。
2012年2月23日8时38分，徐邦达因病医治在北京逝世，享年101岁。徐邦达遗体告别仪式定于2月29日举行。

徐邦达自成一家的行书，给人以峻拔崎岖、汪洋恣肆的美感。他作书舒缓而有节律，运笔以静制动，不仓促紧迫，不弱也不霸，沉稳自若。他的行书笔墨酣畅淋漓，结体自然舒展，粗壮如牛健步，细密如龙蛇逶迤，线条疏密相间，行中带草，体圆用方，极尽笔法变化。其结体以苏东坡、米襄阳为主，取苏字之态浓意远、米字之尽秀极妍。他上溯李北海以厚其气，下参董其昌以畅其韵，再辅以过目不下数万件书法名迹的滋养，终使作品透溢出一种博大深远的气势和韵味无穷的神采。由于作品中蕴藏着深厚的文化底蕴和人文积淀的人格气质，更使徐邦达的书法在风格上与其他书家拉开了距离。

徐邦达历经七十多年的探索，积多年的体悟和实践，在出入米芾并广取博收集大成后逐渐形成了自家体制。其书体以行为主而略杂草法，结字取法米芾，又汰去米氏夸张、故作姿态的习气，务求圆润婉转，又加之画家的优势，使他的作品墨色清新秀润，线条富有弹性而质感强，观之大有“方寸天地见宇宙，笔走龙蛇写春秋”之气势。

总体评价
细读徐邦达的书法，所散发出来的精神气质与文化涵养，更是富有感染力和生命力的。
人物评价
“徐先生是一位真正继承中国传统的文化人，但又不拘泥于旧的礼数，作为跟随他近四十年的学生，我们到他家就像回家一样，他在做学问或看书的时候，我们就在旁边，他忙完之后我们再谈，他完全没有居高临下的感觉。”——徐邦达弟子、著名鉴定家、书画家萧平
“我们是从事艺术品拍卖的，我们体会最深的是，徐老的鉴定是最受市场认可的，因为他绝不会为利益而趋利避害，在这方面，徐老是一个楷模。”——北京匡时拍卖总经理董国强
“随着鉴定“五老”的全部离去，艺术拍卖品市场将呼唤更多专业鉴定团队的出现，依赖于权威和专家的个人眼力和声望的时代已经结束了，今后将不会再出现某个专家说了就算的局面。”——中央财经大学拍卖研究中心名誉主任王凤海则
“徐半尺”名号
在业内，徐邦达老先生被称为“徐半尺”。据徐老的学生著名鉴定家王连起说，这个名号准确地说是从1991年开始传播开来的，那年徐邦达老先生到台湾为博物馆做书画鉴定，因徐先生书画鉴定能力极高，可谓火眼金睛，往往被鉴定的书画作品刚刚展开半尺，徐老便已辨出真伪，由此得了“徐半尺”的名号。

A rich collection of juvenile is in contact with a large number of ancient and modern calligraphy. Fourteen years later, began to study painting, and into the sea when the famous calligraphy painter, connoisseur Mr. Wu Hufan, calligraphy and painting and appreciation day, less than thirty years, that is good at learning ancient paintings known to the south of the Yangtze river. In 1937 to assist Shanghai City Museum for "Shanghai Literature Exhibition" in ancient paintings collection, sorting and display work, Mr. Ye Gongchuo asked to write "the ancient painting abstract directory".
Author of "Introduction", "ancient paintings identification of ancient paintings study", "pseudo false ancient paintings now to be recorded", "the old" painting from the collection of restatements etc.. In old age more than pick up test, brush, landscape, elegant charm show run deep. Classical poetry. Former the Imperial Palace Museum researcher.
February 23, 2012 8:38 died.

Xu Bangda, born in Shanghai in 1911. Father Xu Yaochen, silk merchant, but like the collection, the home of its rich, Xu Bangda was deeply influenced the.
At the age of fourteen began to study painting, from the old Suzhou painter Li Tao (zuishi) to study painting, from Zhao Shiwang (Uncle Ru) to study the ancient paintings and calligraphy identification knowledge. Later, when the sea and into the famous painter and calligraphy connoisseur Mr. Wu Hufan gates.
In 1937 to assist Shanghai City Museum for "Shanghai Literature Exhibition" in ancient paintings collection, sorting, Chen Liezhi, Mr. Ye Gongchuo's writing of "the ancient painting abstract directory".
In 1946 the Chinese fine arts, director of Shanghai City branch, while employed will consultant for the Art Museum of Shanghai city reconstruction committee.
In 1947 has held solo exhibitions in Shanghai China huayuan.
By 1949, Shanghai City, Cheng advisor.
In 1950, the State Bureau of cultural relics Zheng Zhenduo recommended to the Cultural Relics Bureau work.
After 1953, transferred to the the Imperial Palace Museum of ancient calligraphy and painting appraisal work.
In 1953, around the collection and acquisition of 3500 pieces of precious paintings and calligraphy works as the foundation, the reconstruction of the Imperial Palace Museum painting museum.
At the beginning of 1978, the State Bureau of cultural relics should be about to participate in the national painting and calligraphy heritage expert group for museums throughout the country national identification of precious cultural relics, and assume the responsibility of students.
Lasted eight years, into the "ancient Chinese painting and calligraphy drawings" multi volume.
After 1980s, many visits to the United States, Australia, Canada and other countries, investigate the loss of overseas Chinese painting and calligraphy and academic exchanges with foreign experts, made a number of academic achievements.
February 23, 2012 8:38, Xu Bangda illness treatment died in Beijing, at the age of 101. Xu Bangda remains farewell ceremony is scheduled for February 29th.

Xu Bangda and his script to JUNBA, rugged beauty, freely. He made the book soothing and rhythm, brush to brake, not hasty pressing, not weak nor tyrants, calm calm. His script text structure of natural stretch, fully and delightfully, stout like cattle with fine lines, such as snake winding density and white, line with grass, with round body, his style change. The body of Su Dongpo, MI Xiangyang, Su Zi States much, as the word show extremely yan. He traced Li Beihai to the thick gas, ginseng by Dong Qichang Chang Qiyun, supplemented by a famous calligraphy not tens of thousands of pieces of nourishment, eventually make works through overflow a profound momentum and the infinite charm of the spirit. Because the work contains profound cultural heritage and cultural personality temperament, make Xu Bangda's calligraphy style and other calligraphers apart.
Xu Bangda after more than and 70 years of exploration, accumulated experience and Practice for many years, in the entry and wide collection of Big Bo Mi Fu take after gradually formed their own system. The main body behavior and slightly weed, the word node by Mi Fu, and eliminating Michaelis exaggeration, posturing to habit, mellow and mildly, the painter's advantage, make his works show fresh ink lines smooth, elastic and strong texture, in view of a "heart space to see the universe, write good penmanship. The spring and Autumn" momentum.
Overall evaluation
Reading Xu Bangda's calligraphy, ethos and culture comes out, it is full of appeal and vitality.
Character evaluation
"Mr. Xu is a real China traditional culture inheritance, but not rigidly adhere to the old etiquette, follow him as a student for nearly forty years, we went to his home just like back home, when he was learning or reading a book, we will in the next, when we talk about him, he did not condescending." - Xu Bangda disciples, famous connoisseur, painter, Xiao Ping
"We are engaged in the art auction, our experience is the deepest identification of old Xu is the most recognized by the market, because he will never go for the benefit of, in this regard, the old Xu is a model." Beijing auction Kuang general manager Dong Guoqiang
With the identification of "five old" of all gone, art auction market will call more professional appraisal team, rely on the authority and the expert's eyesight and prestige of the era is over, the future will no longer appear some experts say if the situation." - Central University of Finance and Economics auction Research Center honorary director Wang Fenghai
The name "Xu Banchi"
In the industry, Mr. Xu Bangda was known as "Xu Banchi". According to the students' famous connoisseur Wang Lianqi Xu said, this name is precisely from the beginning of 1991 spread, when Mr. Xu Bangda went to Taiwan to do the identification of painting as a museum, because Mr. Xu is high appraisal ability, often identified piercing eye, calligraphy and painting works has just begun half a foot, the old Xu has been identified the authenticity, which won the "Xu half foot" name.