Abstract: 　Objective　To explore the factors influencing serum trough concentration of vancomycin in pediatric patients with severe gram-positive cocci pneumonia. Methods　The general information, the biochemical test results, and plasma concentration of vancomycin were collected from 93 pediatric patients with severe gram-positive cocci pneumonia. The relative factors influencing trough concentration of vancomycin were analyzed retrospectively.  Results　With the dosage of 40-60 mg/ (kg·d), serum trough concentration of vancomycin were between 10-20 mg/L in 26 patients, <10 mg/L in 54 cases, ≥20 mg/L in 13 cases. The ALT, AST, GFR, and γ-GT were significantly different among three groups (P<0.05); the 10-20 mg/L group had the highest levels of AST and γ-GT, the ≥20 mg/L group had the highest level of ALT and the lowest level of GFR. Multiple linear regression analysis showed that GFR was negatively linearly correlated with the serum trough concentration of vancomycin (R2=0.039, P<0.05). The median serum trough concentration of vancomycin in pediatric patients with GFR≥90, 60?90, 30?60 mL/(min·1.73m2) were 8.66, 18.21, 8.45 mg/L respectively, and the difference is statistically significant (P<0.05). Conclusions The serum trough concentration of vancomycin is negatively linearly correlated with GFR in pediatric patients with severe grampositive cocci pneumonia. The patients with impaired renal function are easier to reach the target serum trough concentration of vancomycin. Clinical use of vancomycin should follow the low doses in the range the guideline recommended, and the serum trough concentration should be closely monitored.