Fang Yizhi (1611-1671, named Yaodi Yuzhe after his renunciation of mundane life), was a disciple of Chan Master Juelang Daosheng (1592-1659). Fang had a vast range of learning, and he contributed his own keen insights into many fields. He did not reify thought, and held that every source of knowledge should be a therapeutic method for study, emulation and practice; with composition and arrangement through his unique wisdom, new inspirations and effects could be produced. For this reason, labels such as “Confucian,” “Buddhist,” “monk,” “scientist,” “textual scholar,” or “Neo-Confucian” are insufficient to convey the depths of his scholarship. Although Fang’s thoughts underwent different phases of development through the stages of his life, his thought about Chan was rather consistent. Departing from the Linji school, headed by Master Miyun Yuanwu, which considered the unlearned as superior to the learned and treated classics and doctrines as enemies, Fang held that since Chan study is derived from Buddhist study, study on classics is to be emphasized. To change the prevailing views, he chose Huayan teachings as the most appropriate approach. For Yaodi, the philosophy of Huayan was the best connection between Chan and doctrinal approaches, and was also a theoretical base for him to support non-Buddhist studies, and bring them closer to a Chan that uses words. In his view, Chan is without substantial content; it is nothing but a medium to trigger and synthesize a learner’s talents and knowledge. The specific substance of Chan is almost completely contained by Huayan study, which indicates the significance of the study of Huayan to Buddhism and the field of philosophy at that time. This essay argues that Fang Yizhi’s Avatamsaka Zen (Huayan Chan) philosophy is not solely derived from his Master Juelang Daosheng, but rather nourished by the prevalent forest monastic traditions through active dialogue with its Masters such as Hanshan Deqing, Xuelang Hongen, Zibo Zhenke, Miyun Yuanwu, etc. Through an analysis of the sources of Fang’s philosophy, this essay seeks to find a suitable place for him in the history of Zen Buddhism.