【Objective】 To analyze the environmental monitoring results of NAT laboratory from 2016 to 2019 and evaluate the influence of environmental quality on blood screening. 【Methods】 Monthly/Quarterly environmental monitoring was carried out in NAT laboratory regularly by means of air deposition and surface wiping. The monitoring results were statistically analyzed and comprehensively evaluated in combination with the pool/multiplexNATreactiverate and discriminatory/resolutionrate. 【Results】 A total of 48 batches of environmental monitoring tests were conducted from 2016 to 2019, 11 (25 reactive sites) were unqualified, including 15 reactive sites (60%) as the hallway doorknob or access control, which were the public areas shared with serology laboratory, and these sites were not reactive for 6 consecutive months after intensive cleaning and disinfection. In Nov.2017, the air deposition in biosafety cabinet and surface wiping of Cobas s 201 were reactive, and the restwere the doorknobs. Pearson correlation analysis showed that there was no correlation between the positive rate of environmental monitoring and the detection amount, the pool/ multiplex NAT reactive rate and discriminatory/resolution rate. 【Conclusion】 The accidental environmental pollution in the laboratory is not related to the detection amount and positive rate, indicating that the cleaning and anti-pollution measures are timely and effective to ensure the accuracy and reliability of the screen results. NAT laboratory should gradually establish and improve the environmental monitoring system according to the layout and environment so that the environmental quality meets the testing conditions.