Objective To investigate the relation between the sites of colorectal cancer and liver metastatic distribution. Methods The enhanced multiple-slice spiral CT images and clinical data of 105 cases diagnosed colorectalcancer with liver metastases admitted from January 2010 to April 2012 were analyzed retrospectively. Primary site of the tumor， numbers of the metastases on CT images， and the anatomical position of the inferior mesenteric vein （IMV） terminates were recorded. Results ①The ratio of metastases in the right and left hemiliver was 2∶1 for 38 right-sided primary tumors as compared with 1.2∶1 for 67 left-sided primary tumors. The pattern of lobar distribution was significantly different in the two groups （χ2=8.709， P=0.003）. ②In the left-sided colon cancer group， the ratio of metastases in the right and left hemiliver was 65∶98 for 28 patients with IMV terminating in splenic vein （SpV）， 116∶52 for 36 patients with IMV terminating in superior mesenteric vein （SMV）， and 13∶15 for 3 patients with IMV terminating in the junction of SMV and SpV. The pattern of lobar distribution was significantly different among the three groups （χ2=28.575， P=0.000）. Further comparison between the former two groups， the difference was statistically significant （χ2=27.951， P=0.000）. ③In 25 patients with IMV terminating in SpV， the metastases of 19 cases were mainly distributed in the left lobe of liver （P=0.001）；In 34 patients with IMV terminating in SMV， the metastases of 25 cases located mainly in the right hepatic lobe （P=0.000）. Conclusions Right-sided colon cancers selectively involve the right lobe of liver， while left-sided tumors selectively involve the right lobe of liver when its IMV terminates in SMV and involve the left lobe when its IMV terminates in SpV， respectively. The discovery may help shorting the diagnostic workup in patients presenting with liver metastases from an unknown primary site， and may improve the detection rate of metastases in initial diagnosis and follow-up.