Ou-yi Zhi-xu (1599-1655) a religious thinker of the late Ming, early Qing period, combined various Buddhist schools of thought and lineages to develop a religious system of thought that incorporates Chan, Pureland, Vinaya, and Esoteric schools of thought as well as Tientai, Huayan, and Yogacara. Given his erudition, adherence to precepts, and the joint practice of both Chan and Pureland that Ou0yi Zhi-xu cultivated, what then is the major underpinning of the system of thought which he developed? What particular characteristics does this system have? These are two of the questions this article wishes to address. Owing to the fact that Ou-yi zhi-xu's system of thought is quite broad and comprehensive in scope, this has led to a dispute among contemporary scholars as to the position he holds vis-a -vis various Buddhist schools. In order to further contribute to this discussion we must first look at Ou-yi Zhi-xu's own writings. Therefore, this article will be divided into two sections. The first section will discuss the special characteristics of Ou-yi Zhi-xu's thought while the second section will be devoted to an appraisal of his status and position within Chinese Buddhism. In discussing the characteristics of Ou-yi Zhi-xu's thought, it is apparent that his way of thinking is based on the Tang and Song concept of Liti. This concept is one Ou-yi Zhi-xu's employed in his practice through the use of Yi-nian xin (一念心) (or concentrating the mind). Therefore this article will elaborate on Ou-yi Zhi-xu's conception of litixin and xinxingshuo. In examining Ou-yi Zhi-xu's position within Chinese Buddhism, emphasis will be placed on discussing the assessment of his position by other scholars in the field, especially the Venerable Master Sheng-yen. However, according to the research done by this writer, positioning Ou-yi Zhi-xu vis a vis one school or lineage is indeed problematic. Therefore, this article will address this problem and make a further analysis.