To investigate the effect of Gehua Jiecheng Decoction on the expression of related pro-tumor suppressor genes in mice colon tissue of the " inflammation-cancer transformation" about ulcerative colitis(UC)-ulcerative colitis associated carcinogenesis(UCAC) with spleen deficiency and damp heat syndrome.Among 80 SPF C57BL/6 male mice,10 were randomly selected as blank group (group K),and the other 70 were set up to build the spleen deficiency damp-heat model.After the establishment of spleen deficiency damp-heat model,they were randomly divided into model 1,2,3 cycle group (M1,M2,M3),high,middle,low dose Gehua Jiecheng Decoction group (G,Z,D) and positive control mesalazine group (Y),10 cases in each group.The "inflammation-cancer transformation" about UC-UCAC was further established by azoxymethane(AOM)/dextran sodium sulfate (DSS).Each group was treated with corresponding drugs and the course of treatment was 4 weeks.Then to observed the general condition of mice,counted the body weight of mice,observed the ultrastructure of colonic mucosa under electron microscope,and detected the expression of c-jun,c-fos,c-myc,p53 and RB1 proteins and genes in mouse colon tissues by WB and RT-qPCR,respectively.Compared with the group K,the group M3 mice were in a worse general condition,body weight gain were significantly lower(P<0.01),the colonic mucosal epithelial cell nuclear staining were not uniform,the intracellular mitochondria showed a large amount of hyperplasia and swelling,and the proteins and genes expression of c-jun,c-fos and c-myc were significantly higher(P<0.01).The proteins and genes expression of p53 and RB1 were significantly lower (P<0.01).Compared with the group M3,the general condition of treatment group mice were improved,body weight gain were higher,colonic mucosa epithelial nuclei were relatively uniform,the mitochondria in cells hyperplasia swelling improvements,the proteins and genes expression of c-jun,c-fos and c-myc were lower.The proteins and genes expression of p53 and RB1 were higher.Groups G,Z and Y were in the most significant level(P< 0.01,P<0.05).Gehua Jiecheng Decoction may can inhibit the expression of proto-oncogenes c-jun,c-fos and c-myc,promote the expression of tumor suppressor genes p53 and RB1,regulate cell proliferation and apoptosis,delay the process of inflammation-cancer transformation,repair the damaged colonic mucosa tissue,and prevent the occurrence of UCAC.