He was born in Fujian province, in China, and moved to Japan in 1928. When he naturalized as a Japanese citizen, he used the name Go Izumi (吳泉 pronouced in Japanese.) He later returned to his old name. His surname 吳 (pinyin Wu2) reads the same as 碁 in Japanese. As a result, some Japanese said he was born to play go.
Go Seigen is commonly considered to be among the best to have ever played the game. Mr. Teramoto, Go Seigen's manager, has said "[Go Seigen] is one of three go players who will still be famous several hundred years from now. The other two are Dosaku (1677 - 1702) and Shusaku (1829 - 1862)." 
He is well known, along with Kitani Minoru, as being one of the leading exponents of the shin fuseki, a period of experimentation in the opening of the game that broke away from traditional moves.