Abstract: OBJECTIVE To observe the correlation between the exposure of linezolid to children and the risk of thrombocytopenia. METHODS A total of 108 children who were given linezolid for treatment of infection in Wuhan Children’s Hospital from Jun 2015 to May 2018 were enrolled in the study. The incidence of linezolid-related thrombocytopenia was observed, the parameters of exposure of linezolid such as trough concentration (C_min), peak concentration (C_max)and area under the plasma concentration-time curve from time zero to 24 hours (AUC_0~24h) were determined. The correlation between the exposure of linezolid and the thrombocytopenia was observed by means of receiver-operating-characteristic (ROC) curve, and the probability of incidence of thrombocytopenia was evaluated under different exposure levels by using logistic regression model. RESULTS Totally 24 (22.2%) children had linezolid-related thrombocytopenia. AUC_0~24h was closely associated with the thrombocytopenia, the area under ROC curve was 0.857, and the optimal cutoff value was 387.6 mg/h/L. The children were at high risk of thrombocytopenia when the AUC_0~24h was greater than 387.6 mg/h/L. CONCLUSION The exposure of linezolid is closely associated with the thrombocytopenia, AUC_0~24h is the optimal exposure parameter for prediction of the linezolid-related thrombocytopenia, and it is necessary for the hospital to adjust the dosing regimens based on the parameter so as to prevent severe adverse reactions.