Objective :To properly understand the bacterial distribution and susceptibility to antibiotics in thesinus of nasal sinusitis. Method:The mucosal and secretione in sinus were taken from 135 patients who sufferedwith single nasal sinusitis, by functional endoscopic sinus surgery, were cultured for bacteria. Meanwhile the an-timicrobial susceptibility was determined for ordinary antibiotics. Result: The bacterial growth was present in88.15 % of cases ,mixed bacterial growth was present in 52.10 % of all bacterial ,anaerobe growth was present in39.06％00 of all bacteria． the susceptibility to penicillin was in 53.12%0 of all bacteria and cefaolin was in 87.50%.The susceptibility to metronidazole was in 94.67 % of all anaerobes. Conclusion:We think the method that peni-cillin in combination with streptomycin and metronidazole, sufameth oxazole united with metronidazole, cefaolinadded metronidazole were effective in nasal sinusitis treatment before the antimicrobial susceptive examinationhad been done.