Objective To analyze the unqualified air reasons of laminar flow clean operation room when monitored,to strengthen the prevention and make sure static air of the laminar flow clean operating room air 100％ qualified.Methods Each two of the 100 and 1 000 class laminar flow operation room had unqualified air before November 2013,and our department tried to find the reasons and countermeasures.From December 2013 to February 2014,we monitored air four times after carrying out countermeasures,and compared the qualified rate of operation room air with the air qualified rate before countermeasures used.Results The infection rate of Ⅰ type operative incision were always below 0.2％ in our hospital.After comprehensive improvement of operation room,the air qualified rate was beyond the rate of before improvement 85.7％ with statistical significance (P ＜ 0.05).Conclusions It can increase air qualified rate of laminar flow clean operation room by the operational management,cleaning management,aseptic management for maintaining operation room clean system and the training of air sampling personnel.