ObjectiveTo investigate the health care workers’ （HCWs） knowledge about  nosocomial infection(NI) during “nosocomial infection prevention week” (NIPW). MethodsSurvey on HCWs was carried out by comparing statistics from questionnaires before and after NIPW.  ResultsThe recognizing rate of NI before and after NIPW was 60.13% and 65.66% respectively, the latter was  significantly higher than the former (χ2=91.08, P<0.01),  HCWs’ recognizing rate on hand hygiene achieved the  highest, which was up to 98.86%. Recognizing rate of prevention of occupational exposure after NIPW（60.29%）was considerably higher than that (45.93%) before NIPW (χ2=28.95, P＜0.01）.ConclusionThe recognizing rate of NI of HCWs went up remarkably in NIPW, and should be widely promoted.