Maitreya is a Buddha dominating future in the Buddhism tradition, afterwards Saviour and Beneficence Transference thought was generated when it was influenced by Persia. Maitreya Faith was apparently distinct from Buddhism thought of Hinayana Self-extricating and was a great transition and progress in Buddhism history. The Saviour thought contributed a lot for Maitreya Faith to spread widely with a long lasting vigor in Xinjiang and, afterwards, in inner part of China. Due to its location, Xinjiang was firstly influenced when Buddhism spread eastward. According to the detailed investigation on materials got from Tocharian language, Yu-Tian, Sogdian and Huine languages, we knew that Maitreya Faith was widely spread in Xinjiang and the most intensive areas were Qiuci and Yanqi. Maitreya played an important role in the process of Buddhism was introduced into China from India.