Abstract: In this study one hundred and eighteen cases of colorectal cancer, six cases of colorectal denoma and five cases of control colorectal mucosa were analysed by CMIAS.The results showed that the DNA contents of 2c were 51.9±13.92 in colorectal controlgroup,29.4±13.58 in adenoma group, and 19.92±17.33 in cancer group. By compared the different two groups there are in statistical signicance. Between adenoma andcancer groups, there are no statistical significance in the DNA contents of 5c and 5c. Itgave the evidedce of adenoma with anaplasia freqently. So, preoperative Knowlege ofDNA ploidy abnormalities may be available for treating patients with colorectal cancer.