AIM: By analyzing the teicoplannin serum concentration in patients with severe infection and comparing the monitoring results in patients with hyperrenal function and non-hyperrenal function, to provide reference for clinical rational drug use. METHODS: A retrospective analysis was conducted on 64 patients admitted to the department of critical care medicine of a tertiary level hospital from August 2019 to March 2021, and statistical analysis was performed on the monitoring results of teicoplannin, together with medication information and other biochemical indicators of these patients. RESULTS: Sixty-four patients had total 110 times of drug monitoring. 32.7% of ICU patients had renal hyperfunction, and the average serum concentration was 13.6 mg/L. Nearly half of blood concentrations of the monitored patients could not reach the therapeutic target of teicoplanin. For patients without argumented real clearance, increasing the maintenance dose of teicoplanin can significantly increase the blood concentration. While for those with argumented real clearance, the blood concentration of teicoplanin had no significant difference in different maintenance dose groups. Further correlation study found that the serum concentration of teicoplanin in patients with argumented real clearance was significantly positively correlated to cystatin C level, and significantly negatively correlated to albumin level. CONCLUSION: The incidence of renal hyperfunction in ICU patients is high, and the maintenance dose of teicoplanin 600 mg may not be effective for severe infection. To improve the effect of teicoplanin in severe patients, the drug concentration should be monitored to adjust the dose.