Jerry Yang, co-founder of internet media company Yahoo, is donating $US75 million ($A96m) to Stanford University, which will spend most of the money on a new environmental studies center, the university said on Thursday.

Yang, who started Yahoo in 1994 with fellow student David Filo while working on his doctorate, planned to make the donations over a period of several years, said Howard Pearson, director of Stanford's development office.

It will be the largest of several donations Yang has made to his alma mater, although Pearson declined to say how much he has previously given.