Abstract: OBJECTIVE To explore the incidence and platelet count decline characteristics of drug-induced thrombocytopenia (DIT) in children caused by different categories of antibacterial drugs based on 10 years of real-world data. METHODS A retrospective cohort study was used to select pediatric inpatients(98 301 samples) who used antibiotics at Women's and Children's Hospital, Affiliated to Xiamen University, Xiamen Maternal and Child Health Hospital from January 2013 to December 2022. The DIT samples were screened by the Chinese Hospital Pharmacovigilance System(CHPS). The incidence of DIT, the onset time of platelet count decline, the time when platelet count drops to the bottom, and differences in the severity were compared among groups of different types of antibacterial drugs. RESULTS Among all categories of antibacterial drugs, the top three incidence rates of DIT were quinolones(19.61‰), carbapenems(16.59‰) and glycopeptides(14.34‰). The shortest time for the onset of platelet count decrease caused by carbapenems0.59(0.18, 1.27) d, while the longest time for nitroimidazoles2.71(0.80, 4.06) d. The time of decrease in platelet count to the bottom was similar among different groups, but the proportion of severe adverse reactions was higher in glycopeptides and nitroimidazoles(>28%). CONCLUSION DIT is a common adverse reaction of quinolones, carbapenems, and glycopeptide antibiotics in children. The time characteristics of platelet count decrease vary among different antibacterial drugs converting this information into CHPS triggering rules and embedding that in daily clinical practice may be of great significance for the prevention of DIT.