Abstract: OBJECTIVE To understand the comprehensive performance and operation status of clean operating rooms in hospitals in Yunnan province, and to find out the existing problems, so as to provide basis for scientific management of clean operating rooms. METHODS "Architectural technical code for hospital clean operating department" was mainly applied to be the monitoring and judgment basis, and a total of 34 hospitals including 81 clean operating rooms in Yunnan province were randomly sampled, and field test was used to monitor the cleanliness and microclimate indicators for the in-using clean operating rooms under static condition from Feb. 2017 to May 2017. RESULTS As one of the indicators of cleanliness, the number of dust particle with diameter more than 0.5μm or 5.0μm which were both qualified in clean operating rooms were 0.00% for class Ⅲ hospitals, and 2.38% for class Ⅱ hospitals. The qualified rates of planktonic bacteria were 79.49% for class Ⅲ hospitals and 100.00% for class Ⅱ hospitals, The qualified rate ranking from high to low among all microclimate and other indicators such as differential static pressure indicators were 85.19%(69/81) for relatively humidity, 72.84%(59/81) for temperature, 71.60%(58/81) for noise intensity, 51.85%(58/81) for illumination, and 45.68%(58/81) for differential static pressure. The qualified rates of section wind speed and unevenness of wind speed β in class Ⅰ clean operating rooms were 13.33%(4/30) and 33.33%(10/30). The qualified rates of ventilation frequency and wind speed without blind zone in class Ⅱ and class Ⅲ clean operating rooms were 72.55%(37/51) and 78.43%(40/51). There were no significant differences in the above indicators between the class Ⅲ and class Ⅱ hospitals. CONCLUSION The cleanliness indicators and other related technical indicators of clean operating rooms in hospitals in Yunnan province were not all qualified, especially the qualified rate of dust particles was low unexpectedly. For these reasons, we should strengthen the training of relevant knowledge about how to use, manage and maintain the clean operating rooms among related personnel at all levels of hospitals as soon as possible, so as to strengthen the daily supervision and standardized management of clean operating rooms.