Abstract：Objective：To observe the short-term curative effect of Cinobufagin combined with Apatinib in the treatment of advanced gastric cancer with second-line chemotherapy failure， and its effect on immune imbalance of T helper (Th) 17/regulatory T cell (Treg) in peripheral blood， serum tumor markers， and related serological indicators. Methods： A total of 82 advanced gastric cancer patients who failed second-line chemotherapy were selected as the study subjects and randomly divided into the observation group and the control group， with 41 cases in each group， using a random number table method. The control group was treated with Apatinib， and the observation group was additionally treated with Cinobufagin on the basis of the control group. The treatment lasted for three courses， with four weeks being one course. The short-term curative effect and toxic side effect were compared between the two groups. The levels of serum tumor markers [carbohydrate antigen (CA) 72-4， CA19-9， CA242， and carcinoembryonic antigen (CEA)]， related strological indicators [vascular endothelial growth factor A (VEGF-A)， epidermal growth factor receptor (EGFR)， and matrix metalloproteinase-9 (MMP-9)]， and levels of Th17 and Treg in peripheral blood were compared before and after treatment. Results： The objective response rate was 36.59% in the observation group， and 24.39% in the control group， there being no significant difference between the two groups (P＞0.05). The disease control rate in the observation group was 73.17%， and 51.22% in the control group， the difference being significant (P＜ 0.05). After treatment，the levels of serum CA72-4，CA19-9，CA242，and CEA in the two groups were decreased when compared with those before treatment (P＜0.05)， and the levels of the above four indicators in the observation group were lower than those in the control group (P＜0.05). After treatment， the expression levels of Th17 and Treg in peripheral blood and the Th17/Treg ratio in both groups were reduced when compared with those before treatment (P＜0.05)， and the above three indicators in the observation group were lower than those in the control group (P＜0.05). After treatment， the levels of VEGF-A，EGFR，and MMP-9 in serum in both groups were decreased when compared with those before treatment (P＜0.05)，and the levels of the above three indicators in the observation group were lower than those in the control group (P＜0.05). The incidence of gastrointestinal reactions，hypertension，leukopenia， thrombocytopenia， proteinuria， fatigue， and hand-foot syndrome in the observation group was lower than that in the control group，and the incidence of leukopenia，thrombocytopenia，and fatigue between the two groups showed significant difference (P＜0.05). Conclusion： The combination of Cinobufagin and Apatinib can effectively down-regulate the serum tumor markers and VEGF-A，EGFR，MMP-9 levels in patients with advanced gastric cancer with second-line chemotherapy failure， correct immune imbalance of Th17/Treg in peripheral blood， improve short-term curative effects， and to some extent reduce the toxic side effects caused by Apatinib.