Objective:To observe the influence of syndrome differentiation treatment of Weichang’an Prescription on the overall survival (OS) and the progression free survival (PFS) of patients with unresectable colorectal liver metastases. MethodsThe clinical data on a total of 131 patients with unresectable colorectal liver metastases were collected and divided into the integrated Chinese and western medicine group(65 cases)and western medicine group(66 cases)by the bidirectional cohort and concurrent control method.The database was established by Microsoft Excel and SPSS 21.0 software.The survival rates of patients within 1,2,3,4,5 years were counted by life-table method；the median OS and PFS were calculated by Kaplan-Meier method and then carried on the univariate analysis,the difference was compared between groups by Log-rank test；the factors with statistically significance in univariate analysis were enrolled in Cox regression analysis and conducted the multivariate analysis.The prognosis related factors of patients with unresectable colorectal liver metastases were screened out.  Results:①The median OS of the western medicine group was 18.5 months and the median OS of the integrated therapy group was 23.2months. There was significant difference on the median OS between the two groups (P=0.006＜0.05). ②Within 1,2,3,4,5 years the survival rates of the western medicine group and integrated therapy group were 69.7% vs 87.2%, 33.3%vs 47.4%, 14.5%vs 28.4%, 1.3%vs 23.7%, 0%vs 0% respectively,which suggested that the survival rate of the integrated therapy group in 5 years was obviously better than that of the western medicine group(P<0.05).③The Cox regression analysis suggested that resection of primary tumor (P=0.003) , chemotherapy (P=0.000) and syndrome differentiation treatment of Chinese medicine(P=0.004) were independent prognostic factors which affected the OS of patients with this disease. The hazard ratio of resection of primary tumorwas 0.433(95%CI:0.251-0.748),chemotherapy was 0.148(95%CI:0.060-0.365),administration with Chinese medicine was 0.532(95% CI:0.347-0.816). ④The median PFS of the western medicine group were 6.1 months,and the median PFS of the integrated therapy group were 9.2 months. There was significant difference on the median PFS between the two groups (P=0.049＜0.05). ⑤The Cox regression analysis suggested that resection of primary tumor (P=0.022) and local treatment of liver metastases(P=0.020) were independent prognostic factors which affected PFS of patients with this disease. The hazard ratio of resection of primary tumor was 0.466(95%CI:0.242-0.895), and local treatment of liver metastases was 0.576(95%CI:0.362-0.918).  Conclusion:The syndrome differentiation treatment of traditional Chinese medicine based on Weichang’an Prescription are effectively protective factors of prognosis；integrated therapy of Chinese and western medicine show a certain advantage on prolonging OS and PFS of patients with unresectable colorectal liver metastases,which needs to be further evaluated by follow-up.