OBJECTIVE： To study the anti-tumor effects of ethyl acetate extract of Ferula sinkiangensis on CT-26.WT orthotopic transplantated tumor model mice and investigate its related mechanism. METHODS： The mice were randomly divided into sham operation group [solvent （tween 80 and edible oil）]， model group （solvent）， cisplatin control group （5 mg/kg）， low-dose， middle-dose and high-dose groups of ethyl acetate extract from F. sinkiangensis （0.375， 0.75， 1.5 g/kg calculated， by ethyl acetate extract from F. sinkiangensis）， with 12 mice in each group. The mice model of CT-26.WT orthotopic transplantation tumor was established in each group except for sham operation group. They were given relevant medicine intragastrically， once every 2 days， for consecutive 10 d a week after surgery. The body weight， tumor weight， tumor pathological section and spleen index were observed in mice； inhibitory rate of tumor was calculated. The serum levels of IL-12p70， IFN-γ， TNF-α， IL-6， MCP-1 and IL-10 in rats were determined by flow cytometry microarray method （CBA）. RESULTS： Compared with sham operation group， orthotopic transplantation tumer model was established successfully in other groups， and body weight of mice was decreased significantly （P＜0.05）. Serum levels of TNF-α， MCP-1 and IL-6 were increased significantly in model group， while IFN-γ and IL-10 levels were decreased significantly （P＜0.05）. Inhibitory rate of tumor were （62.96±12.54）％， （40.74±17.34）％， （45.93±16.74）％， （57.05±14.28）％， respectively. Compared with model group， tumor weight of mice were decreased significantly （P＜0.05）， cells were loosely arranged， as well as mitotic and infiltration of tumor cells decreased in cisplatin control group， low-dose， middle-dose and high-dose groups of ethyl acetate extract from F. sinkiangensis. Spleen indexes of mice were increased significantly in cisplatin control group， middle-dose and high-dose groups of ethyl acetate extract from F. sinkiangensis （P＜0.05）. Serum levels of IL-12p70， TNF-α， MCP-1 and IL-10 were increased significantly in all administration groups （P＜0.05）， while serum level of IL-6 was decreased significantly （P＜0.05）. The serum level of IFN-γ was increased significantly only in high-dose group of ethyl acetate extract from F. sinkiangensis （P＜0.05）. CONCLUSIONS： Ethyl acetate extract of F. sinkiangensis has the effect of inhibiting CT-26.WT orthotopic transplantation tumor model mice， the mechanism of which may be associated with up-regulation of IL-12p70， TNF-α， IFN-γ， MCP-1， IL-10 level and down-regulation of IL-6 level.