Abstract: Objective To verify and analyze the determination limits of a severe acute respiratory syndrome coronavirus 2 nucleic acid determination reagent in 4 determination systems，and to improve the quality of severe acute respiratory syndrome coronavirus 2 nucleic acid determination. Methods One matched determination system and 3 unmatched determination systems were selected，and the determination limit performance was verified by the severe acute respiratory syndrome coronavirus 2 nucleic acid reference material of the National Institute of Metrology，China. The reasons of failed verification systems were analyzed. Results The determination ability of unmatched system 1 was strong，followed by matched system 1 and unmatched system 2. Shortening the time of cell lysis，nucleic acid release and magnetic bead binding and reducing the number of nucleic acid washing affected the determination limit. Conclusions The severe acute respiratory syndrome coronavirus 2 nucleic acid determination reagent selected in this study could pass the determination limit verification. It is urgent for relevant departments to issue production standards and calibration standards for corresponding instruments. Laboratories should pay attention to sample addition amount，the optimization of unmatched systems and the maintenance and calibration of instruments.

Key words: Severe acute respiratory syndrome coronavirus 2, Nucleic acid determination, Determination system, Determination limit, Performance verification