This essay gives explanations for why English is so prevailing in mainland China. Many factors contribute to this over-heated phenomenon. First, the status of the spread of English is illustrated on the basis of statistics. This mania for English Learn-ing is irrational in mainland China. Subsequently, the three main reasons are stated respectively:state planning, individual choice and linguistic imperialism. How the three factors influenced the spread of English in China was drawn from the internal and exter-nal perspectives.