Abstract： This paper introduces the experience of Professor GUO Yong treating colorectal cancer during perioperative period. According to Professor GUO Yong，there exists the characteristic of stage pathogenesis in the perioperative period of colorectal cancer， which includes all stages of adjuvant chemoradiotherapy including the stage before， during and after operation. This paper puts forward five views on the cooperation between Chinese and western medicine for tumor，namely， the essence view of Chinese medicine thinking，the development view of pragmatism and innovation，the realistic view of periodization， the operational view of window technology and the core view of treatment principle of clearing and purification，to guide the clinical practice.