Objective To evaluate the antimicrobial agents usage in a hospital. Methods Forty patients’ medical records were selected for retrospective analysis, patients were discharged in the year of 1998 and 2000 respectively. Results In 1998, antimicrobial resistant rate was higher, 96.25% of patients received antimicrobial agents, antimicrobial cost accounted for 52.38% of the total hospitalization expense; most antimicrobial agents were for treatment, the majority of patients received two kinds of antimicrobial agents simultaneously; in 2002, 93.54% of patients received antimicrobial agents, antimicrobial cost accounted for 50.47% , most antimicrobial agents were for treatment, and majority of patients only received one kind of antimicrobial drugs. There was significant difference in the total usage rate of antimicrobial agents between two surveys. Conclusion Target surveillance on antimicrobial agents usage should be carried out to reduce the overuse of antimicrobial agents and decrease the bacterial resistance.