Abstract: For a long time, clinicians have been paying increasing attention to the differences in the efficacy of anticancer drugs among various patients.The curative effects and possible side effects of chemotherapy are not only related to factors such as age, gender, and drug interactions but also to the expression of the proteins or enzymes involved in the metabolism of chemotherapeutic drugs.Single-nucleotide polymorphism is the most common form of genetic variation.Studies on the correlation between single-nucleotide polymorphism and the effects or side effects of chemotherapy have been increasingly conducted to investigate the differences in the therapeutic effects and side effects of drugs, which are caused by the genetic variations among individuals.However, single-nucleotide polymorphism has not been ascertained as a predictor of the effects and side effects of chemotherapy.The current study reviewed the single-nucleotide polymorphism correlated with fluorouracil, platinum, paclitaxel, and irinotecan, taking chemotherapeutic drugs for malignant gastrointestinal tumor as the example.