Yanshou (904∼975) was born into a family of Wang in Qiantang. He inherited the dharma lineage of Tiantai Deshao (890∼971), the disciple of Wenyi who was the founder of Fayan Sect. Yanshou first spread dharma at Xyedou Shan, Ming Zhou and gradually became well-known. In 960, Qian Hongchu, the king of Wuyue State, appointed Yanshou to take the first abbocy of the newly-built monastery at Lingyin Shan, Hang zhou. Next year, the king also appointed him as the second abbot of the great monastery at Yongming Qiantang. His disciples once exceeded 2,000. He has written many books including the 100-fascicled Zong Jing Lu, the 3- fascicled Wan Shan Tong Gui Ji, the one-fascicled Wei Xin Jue, the 4-fascicled Zhu Xin Fu, and the one-fascicled Guan Xin Xuan Shu. In these books, on one hand he described systematically the essence of Ch'an Sect, i.e. "to transmit mind with mind and not to attach to words," "to point directly at man's mind and to see the mind- nature to become Buddha"; on the other hand, he took reference from other Buddhist sects to discuss the mind-nature theory and practice techniques in details. He suggested to integrate the two in order to link ch'an and teachings as well as to practise principle and phenomenon at the same time. The theory of Yanshou's ch'an techniques claims "to regard mind as the principal," i.e. to consider mind as "the superior," "the substance," and "the wisdom." In other words, he exalted the Buddha- nature theory of Mah?y?na Buddhism as the standard to observe and explain everything of the world, the human society, the defilements, the birth-death and liberation problems of sentient beings; he took the mind-nature theory of Ch'an Sect as the center to comment the teachings of Mah?y?na and Hinay?na Buddhism and the doctrine of different schools. According to Yanshou, among the Buddhist sects established in Sui and Tang Dynasties, only the doctrine of Huayan School accords most with Ch'an Sect. Through the reference to Huayan School's theories of suchness (the tath?gata mind, the dharma nature), dependent origination of dharma realm, perfect integration of noumena and phenomena, and "the inter-penetration of the true and the delusive," he described that the Buddha nature is the reality of the world; that it is inter-being and inter-penetration between mental defilements and enlightenment, the other shore of liberation and the this shore of mundane, the sentient beings and the Buddha, etc. He also provided the theoretical basis for his "mutual practice of noumena and phenomena," and "integration of ch'an and doctrine" through this kind of inference. Since the noumena and phenomena are perfectly integrated, the self realization of mind-nature and the practice of various teachings should go hand in hand with no obstruction; the Ch'an Sect whose objectives are "to transmit the mind" and "to see the nature" should also harmonize with other schools of teachings. Yanshou is the first one to point out the concept of "understanding the mind." According to him, "understanding the mind" means the same as "seeing the nature," "understanding the objective," and "realizing the nature." They all mean the realization of self nature (Buddha nature, Tath?gata-garbha, self-nature pure mind), and the understanding of Buddha's existing in one's mind. He claimed that a ch'an monk should practise not only "the noumena deeds" but also "the phenomena deeds." Meanwhile, he expounded the Huayan School's spontaneous teaching of "perfect integration." He claims that once one realizes the Tath?gata self-nature, one is enlightened and liberated immediately, i.e. "realizing the mind to become Buddha," "becoming Buddha at one thought." However, Yanshou also emphasized the real life and opined that one should practise the six p?ramit?s and the infinite virtues, and experience the different stages of realization. This has never been mentioned by the ch'an masters before him.