Abstract: Abstract: Objective To estimate and optimize the dosage regimen of vancomycin and linezolid for treatment in different Gram-positive cocci infections. Methods The pharmacokinetic data of vancomycin and linezolid were collected, and the pharmacodynamics in vitro of these drugs for staphylococcus epidermidis, staphylococcus aureus, enterococcus faecalis and enterococcus faecium were analysed. The cumulative response fraction (CFR) was evaluated in different dosage regimens of two drugs against four types of bacteria. Results The regimen of 3 500 mg/d vancomycin was recommended for patients with staphylococcus epidermidis infection. The regimen of 2 500 mg/d vancomycin was recommended for patients with staphylococcus aureus infection. The regimens of 3 000 mg/d vancomycin and 400 mg linezolid given 2 times/day were recommended for patients with enterococcus faecalis infection. The regimens of 2 500 mg/d vancomycin and 400 mg linezolid given 2 times/day were recommended for patients with enterococcus faecium infection. Conclusion In application of vancomycin and linezolid for treatment of Gram-positive cocci infections, different dosage regimens should be used in different types of infections.

Key words: Vancomycin, Gram-positive bacteria, Linezolid, Monte Carlo simulation