OBJECTIVE：To ev aluate pha rmacoeconomics of magnesium isoglycyrrhizinate preventing liver damage induced by chemotherapeutic drugs for gastric cancer ，and to provide reference for rational use of liver-protecting drugs. METHODS ：Totally 200 inpatient medical records were collected from our hospital retrospectively during Jan. 2018-Feb. 2020，and then divided into group A （prophylactic use of magnesium isoglycolate ，50 cases），group B （prophylactic use of magnesium isoglycolate combined with TCM prescriptions ，50 cases），group C （prophylactic use of polyene phosphatidylcholine ，50 cases） and group D （non-prophylactic use of liver-protection drugs ，50 cases）. The effects （total response rate ）of four plans preventing liver damage were evaluated. Pharmacoeconomic evaluation was analyzed by cost-minimization analysis and cost-effectiveness method ， sensitivity analysis was carried out at the same time . RESULTS ：Total response rates of group A ，B，C and D were 94.00％， 96.00％，82.00％ and 72.00％. The total response rates of group A and B had no statistical significance （P＞0.05），but were significantly higher than those of group C and D （P＜0.05）；total response rate of group C was significantly higher than that of group D （P＜0.05）. The costs of groups A ，B，C and D were 1 936.70，2 086.96，1 800.91，2 975.42 yuan. The cost-minimization analysis was used to compare the therapeutic plan of group A and B ，and plan of group A was more economical. The cost-effectiveness method was used to compare therapeutic plan between group C and D ，and the plan of group C was more economical. The cost-effectiveness method was used to compare therapeutic plan between group A and C ，and the cost-effectiveness ratio of 2 groups were 2 060.32 and 2 196.2 3，incremental cost-effectiveness ratio was 1 131.58，and the plan of group A was more economical. Above conclusion were supported by the results of sensitivity analysis. CONCLUSIONS ：The cost-effectiveness of magnesium isoglycyrrhizinate preventing liver damage induced by chemotherapeutic drugs for gastric cancer is better than magnesium isoglycyrrhizinate combined with TCM prescription ， polyene phosphatidylcholine and non-prophylactic use of liver-protecting drugs ，showing economical advantage.