The invention discloses a kit for detecting the medicinal effect of warfarin by utilizing rs9934438. The kit comprises a MassARRAY chip, and three primers for detecting the gene VKORC1rs9934438SNP site are respectively called as a forward primer, a reverse primer and an extension primer with the sequences respectively shown as SEQ ID No.1-3 in sequence, wherein the primers are polymorphic sites for identifying the medicinal effect of warfarin and adverse reaction related genes. The kit disclosed by the invention can be used for carrying out high-throughput detection on the sites and has the advantages of high sensitivity, high specificity, stable detection results, high reliability and the like; and meanwhile, the kit is suitable for the gene analysis fields of clinical disease mutation detection, pharmacogenomics analysis, medicolegal expertise and the like.