Objective To explore the influencing factors of the qualification rate of central air-conditioning ventilation system by analyzing the sampling results of central air conditioning ventilation system in public places. Methods 22 public places using central air conditioning ventilation system in Hefei were randomly selected to detect the inhalable particulate matter (PM₁₀),total bacteria,total fungi,fresh air volume,total number of bacteria on the inner surface of air duct,total number of fungi on the inner surface of air duct,dust amount on the surface of air duct,Legionella pneumophila in cooling water and condensate water.Detection and evaluation based on the “hygienic code for Central Air Conditioning and Ventilation System in Public Places” (WS 394—2012). Results was no statistically significant difference in the qualified rate of testing indicators in hotels and other places (P_Fisher = 1.000).The total number of fungi in the air conditioner supply air had the lowest qualified rate of 77.27%,followed by the total number of bacteria in the air conditioner supply air with a qualified rate of 81.82%.The qualified rates of the total number of bacteria and fungi on the inner surface of the air conditioning duct were 95.45%,and the qualified rates of the other indicators were 100.00%. Conclusion The qualified rate of sampling inspection of central air conditioning ventilation system in Hefei is not optimistic,and the microbial pollution of air supply is the main factor affecting the qualified rate.