Objective To study the anti?tumor effects and mechanisms of celecoxib and pentoxifylline on Lewis lung carcinoma (LLC) in mice. Methods Mouse tumor models were established by subcutaneously injecting cultured LLC cells, which were divided into two groups. The control group was administered solvent, and the experimental group was administered celecoxib and pentoxifylline. The tumor size and volume were measured twice a week to observe the tumor inhibitory effect of celecoxib and pentoxifylline. Pathological changes were observed by immunohistochemistry, and the expression levels of COX?2, Bid and Caspase?9 proteins were measured by Western Blot. Results Celecoxib and pentoxifylline had an inhibitory effect on LLC in mice. The median survival of the experimental group was higher than that of the control group, which was related to inhibition of angiogenesis and induction of LLC cell apoptosis. Conclusions Combined celecoxib and pentoxifylline inhibited LLC growth in mice by suppressing angiogenesis and inducing tumor cell apoptosis.