Buddhist transmission was an important cultural phenomenon in Asian history. Up to the present, scholars have maintained that Buddhism was transmitted to China through the efforts of merchants, Buddhist monks and priests who travelled between India and China. In this paper I attempt to show that Buddhism was transmitted into China mainly because some Chinese emperors wanted to establish a Buddhist kingdom or to implement Buddhism as their ruling religion. From the time Kujūla Kadphises' (c. 5BC-78AD) first used Mahāyāna Buddhism to rule the Kushāns (c.30-300), Mahāyāna Buddhists have documented the image of a cakravartin (he who rules with Buddhism) and the method for establishing a Buddhist kingdom in texts which were composed in every period of its development. In this regard, whenever a Chinese emperor wanted to rule with Buddhism, he had first to find an eminent monk to help him import and translate the relevant texts. Following this, emperor and monk had to work very closely together to promote Buddhism in the kingdom. Both kinds of Buddhist activities were the main cause of Buddhism being transmitted to China. In other words, Buddhism was transmitted into China for political reasons.