We calculate the CEA doubling time of liver metastasis (13 cases) from colonic cancer and studied the factors influencing the growth rate. The doubling time of liver metastasis from colonic cancer ranged from 10 to 112 days (mean 57.8 +/- 35.4 days) was found significantly different among differentiations in histological type. Namely, the doubling time of poorly differentiated adenocarcinoma was shorter than that of well differentiated adenocarcinoma. Moreover the postoperative survival time (Y: months) was found to be significantly correlated with doubling time (X: days); Y = 0.155X + 4.452, r = 0.718, p less than 0.05. These results suggest that the growth rate calculated as CEA doubling time of cancer plays an important role in determining the degree of biological behavior in colonic cancer patients.