Although both of them are alien religious cultures and equally enjoy long spreading histories in China, Christianity and Buddhism have had quite different fates in Chinese culture:totally merging in Chinese culture,Buddhism,together with Confucianism and Taoism,helps to shape Chinese mainstream culture,while Christianity has never been successful in merging itself organically into Chinese culture,still remaining a little marginal to Chinese mainstream culture even today.This paper argues that the reasons lie, compare with Buddhism,in the different culture - topgraphical features of Christianity as a religious culture especially as relevant to Chinese cultural - topgraphical, its different spreading strategy,the different spreading chances it happened to have and its different world view.