Objective To investigate the clinical characteristics and prognosis of patients with synchronous or metachronous liver metastasis of colorectal cancer. Methods Clinical data of patients with colorectal cancer liver metastasis from 1994 to 2006 in the First Affiliated Hospital of Sun Yat-Sen University was retrospectively analyzed. The Kaplan-Meier method and long-rank test were used for bivariate comparisons. Multivariate analysis was done by the Cox regression model (Backward Wald). Results A total of 486 patients with colorectal cancer liver metastasis, including 191 synchronous and 295 metachronous liver metastasis, were analyzed. The overall 5-year cumulative survival rate was 16.2%, 9. 3% forsynchronous and 21.5% for metachronous liver metastasis respectively ( P ＜ 0. 01 ). Liver metastasis was surgically resected in 267 patients, 151 received radiofrequency ablation and 68 underwent conservative therapy with 5-year cumulative survival rates of 22. 1%, 10. 3% and 0 ( P ＜ 0. 01 ) respectively. On univariate analysis, poor prognosis was associated with older age, synchronous metastasis, higher serum CEA level, advanced N stage and poor differentiation of the primary tumor, bowel obstruction, ascites, tumor longitudinal length over 8cm, non-surgery therapy. Multivariate analysis indicated that synchronous metastasis, serum CEA level, ascites and therapy method were independent prognosis factors. Conclusions The time at which a metastasis occur, serum CEA level,ascites and curative surgical therapy determine the prognosis of patients with colorectal cancer liver metastasis. Surgical resection of metastasis in selected patients could prolong survival.