一般而言，曹洞宗是因開創者良价、本寂師徒先後在江西洞山、曹山傳法而得名，屬於南禪青原行思法系，中經石頭希遷、藥山惟儼、雲巖曇晟以至良价。良价弟子本寂繼承師業，大成禪法。曹洞禪法上承希遷的理事「迴互」（相應互涉），進而擴充為「五位君臣」說，從理事、體用關係上闡明理事不二、體用無礙的義理。曹洞宗的思想是以「即相即真」（從事相中顯示理體）為理論基礎，以「偏正回互」為根本宗旨，其「偏正回互」、「兼帶正偏」的宗旨，乃源自華嚴宗的「理事圓融」、「理事無礙」論。「正」是指理體，「偏」是指事相，「偏正回互」、「兼帶正偏」實即「理事無礙」、「理事圓融」。理事圓融意指佛法真理與世間事物絕非對立，二者是一而二、二而一的關係，它確立了本體與現象的統一哲理。根據此一哲學前提，才有曹洞宗「偏正回互」、「兼帶正偏」的禪旨。宋元以來，曹洞宗禪師大多以《華嚴經》的圓教一乘與華嚴宗的理事無礙，來統攝其禪學思想，並將華嚴宗的理事同界與曹洞禪的正偏同位聯繫起來，而呈現其「兼帶正偏」的特殊禪思。本文僅就宋元時代曹洞宗義青、清了、正覺、行秀等禪師的相關著作，探究其禪法的華嚴意涵，以彰顯此一時代曹洞禪法的特色。

The Caodong lineage of the Chinese Chan school takes its name from a combination of the abbreviated names of its two founders, Dongshan Liangjie (807-869) and Caoshan Benji (840-901). It belongs to the Southern Chan lineage beginning with Qingyuan Xingsi, which was transmitted through Shitou Xiqian to Yaoshan Weiyan and Yunyan Tansheng, and eventually to Liangjie. Liangjie's disciple Benji continued and further developed the Chan style of his master. The Caodong school teaches the identity of phenomena and reality, i.e. the relative and absolute aspects of reality. This thought is expressed in Liangjie's ”five ranks” stanzas, which explain the relationship of the ”bent” (the relative) and the ”straight” (the absolute). This Caodong thought originated in the Huayan school's concept of ”complete harmony of absolute and relative”. This paper examines the characteristics of Huayan thought in works of important Caodong masters during the Song and Yuan dynasties: Yiqing (1032-1083), Qingliao (1090-1151), Zhengjue (1091-1157), and Xingxiu (1166-1246).