Abstract: A collaborative inter-laboratory validation was carried out using a reporter gene assay to measure the bioactivity of anti-PD-1 monoclonal antibody, in order to study the applicability and transferability of the method. In this study, two collaborative schemes were designed to measure the precision, linearity and accuracy of the method. The results showed that the 95% confidence interval (CI) of the intra-assay precision was (1.72-16.89)%, inter-assay precision was (2.63-17.67)%, inter-laboratory precision was (9.00-14.26)%, all linear correlation coefficients were greater than 0.99, and the 95% CI for the accuracy at different potency levels was (91.83-104.40)% at 50%, (90.40-101.40)% at 75%, (94.71-105.60)% at 100%, (94.00-102.00)% at 125%, and (96.73-104.30)% at 150%. The collaborative validation results proved that the reporter gene assay for the bioactivity determination of anti-PD-1 monoclonal antibody has good precision, linearity and accuracy, and could be applied to the release and stability analysis of anti-PD-1 monoclonal antibodies in different laboratories.