This paper delved into the influence of Mahāprajñāpāramitopadeśa (hereafter abbreviated as MPPU) on Zhiyi's interpretation of Chan as well as the philosophical implication within through the investigation of the citation of MPPU in his interpretation of Chan. This paper points out that the influence of MPPU on the Zhiyi's interpretation of Chan can be induced into three points: 1. The early stage whereby Zhiyi selectively adopted the theories of meditation of the Early, Abhidharmic and Early Mahāyāna Buddhism from MPPU, and then systematically constituted his interpretation of Chan. 2. The doctrine of the contemplation of mind (kuan-hsin) from Zhiyi's interpretation of Chan, which can be traced back to MPPU, and from that he developed the Perfect Sudden Teaching (Yuan-Tun-Chih-Kuan). As regards, MPPU did influenced the Chan interpretation, the doctrine of the contemplation of the mind and even the Perfect Sudden Teachings of Zhiyi 3. Although the works of the middle and late stages of Zhiyi did not adopted from MPPU as the ground of his interpretation of Chan, and also even more valued on other Mahāyāna texts. But if consider the model shown as the early stage, the middle and late stages of Zhiyi's interpretation has never been divorced from this kind of pattern. Accordingly, MPPU did play an important role in Zhiyi's Chan interpretation.
