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.