Objective:To observe the colitis-related precancerosis of colonic carcinoma and apoptosis treated by Yangyin Huayu Jiedu decoction.Method: Forty mice were randomly divided into control group

model group

Yangyin Huayu Jiedu dicoction prevention group（18.72 g·kg-1 ig for 7 weeks

starting from the beginning of model inducement）

treatment group（18.72 g·kg-1 ig for 7 weeks

starting from the established model）.Model of colitis-related precancerosis of colonic carcinoma was established by intraperitoneal single injection of azoxymethane（AOM） and feeding of dextran sulfate sodium（DSS） in drinking water（7 days later after AOM injection） for 7 days in three groups of mice except the controls.The colitis-related precancerosis of colonic carcinoma and apoptosis treated by Yangyin Huayu Jiedu decoction was investigated.Result:Yangyin Huayu Jiedu decoction of prevention and treatment groups showed significant improvement of colitis-related precancerosis of colonic carcinoma;Apoptosis index（AI） in the prevention group and the treatment group showed significant difference compared with that in model group（P<0.01）.AI of treatment group showed significant difference compared with that of prevention group（P<0.01）.Conclusion:Yangyin Huayu Jiedu decoction can be used for prevention and treatment of colitis-related precancerosis of colonic carcinoma.The mechanism might be related to promoting apoptosis in lesion cells.