OBJECTIVE To analyze the adverse drug reaction （ADR）signals of ado-trastuzumab emtansine and brentuximab vedotin，so as to provide reference for clinical medication safety. METHODS Using the FDA adverse drug event reporting system （FAERS）database and OpenVigil 2.1 data platform ，the ADR of the two drugs were collected from being approved by FDA to the Sep. 30th，2021. The ADR signals were detected by frequency method and sorted according to the occurrence frequency and signal strength respectively. RESULTS & CONCLUSIONS A total of 2 319 and 3 178 ADR reports related to ado-trastuzumab emtansine and brentuximab vedotin were collected ，215 and 329 ADR signals were detected respectively. According to the occurrence frequency，the most frequent ADR s of the two drugs were thrombocytopenia （109 cases）and febrile neutropenia （198 cases）， separately，which were consistent with the drug instructions. According to the signal strength ，the spider nevus of ado-trastuzumab emtansine（report odds ratio of 451.46）and the noninfectious endocarditis of brentuximab vedotin （report odds ratio of 304.35） ranked first ，both of which were not reported in the drug instructions. It is suggested that attention should be paid not only to the most common ADR s of blood and lymphatic system caused by both drugs ，but also to the ADRs not reported in the drug instructions such as spider nevus of ado-trastuzumab emtansine and noninfective endocarditis of brentuximab vedotin.