A retrospective study investigating 1198 cases of colorectal cancer was undertaken to ascertain whether the site distribution pattern of colorectal cancer changed according to time trends and was influenced by age and/or sex. These patients were divided into two groups according to two five-year calender periods from 1979 to 1988 (group A: 1979-1983; group B: 1984-1988). In both groups, a considerable portion of cancers were located in the rectum (group A: 50%; group B: 51%). Comparing these patients, we found no significant change in site distribution between these two groups (p=0.34), neither was there any significant change in the distribution pattern by sex among patients of the same or different groups. The percentage of old patients above the age of 70 in the right colon cancer group remained unchanged between these two calender periods (14% vs. 14%). But both male and female patients of group B were significantly older than those of group A (male: 60.6±1.9 vs. 56.0±2.6; female: 57.7±2.1 vs. 54.6±25; p＜0.05). We conclude that in spite of increase in number and mean age of patients with colorectal cancer which was thought to be the consequence of longer life expectancy, analysis of our data did not give support to the pheonomenon of ”aging gut” or rightward shift of colon cancer observed in western countries.