The present invention relates to pyridino pyrimidine derivatives, preparation method and medical use thereof. Specifically, the present invention relates to pyridino pyrimidine derivatives of general formula (I), pharmaceutically acceptable salts thereof, and the preparation methods thereof, as well as their use as a cancer therapeutic agent, especially their use as a CDK4 and/or CDK6 inhibitor, wherein each substitute of general formula (I) is defined as the specification.本發明涉及吡啶並嘧啶類衍生物、其製備方法及其在醫藥上的應用。具體而言，本發明涉及一種通式(I)所示吡啶並嘧啶類衍生物及其可藥用鹽，其製備方法以及它們作為癌症治療劑特別是作為CDK4和/或CDK6抑制劑的用途，其中通式(I)中的各取代基的定義與說明書中的定義相同。
