This is a collection of research papers published in various mathematical journals by friends, colleagues and former students of Professor Buchin Su in honor ofhis 80th birthday and 50th year of educational work.Professor Su was born in 1902 in Pingyang County, Zhejiang Province, People's Republic of China. He received the degree of Bachelor of Science inmathematics from Tohoku University, Sendai, Japan in 1927, and the degree ofDoctor of Science from the same university in 1931. After returning to Chinain 1931, he first taught at Zhejiang University in Hangzhou until 1952 when thewhole College of Science of Zhejiang University was merged into Fudan Universityin Shanghai. During his 50 years of educational work besides teaching, he alsohas taken up various administrative positions serving as Chairman, Dean, VicePresident and finally the President of Fudan University in 1978.