Abstract: Despite the rapid development of antitumor drugs, the limited drug response rate and adverse drug reactions have severely limited their clinical application. In recent years, the concept of "pharmacomicrobiomics" has emerged, and more and more studies have shown thatmicrobiota plays an important role in the treatment of antitumor drugs. Herein, the interaction between microbiota and antitumor drugs is reviewed from the aspects of chemotherapeutics, molecular targeted drugs and immunotherapy drugs. The mechanism involves immune regulation, hormone regulation, metabolite regulation, drug biotransformation and transmembrane transport regulation. The microbiota regulation strategies that can improve the efficacy and reduce adverse reactions of antitumor drugs are reviewed, in order to provide reference for the individualized treatment of clinical antitumor drugs.