Abstract： Palivizumab(Synagis)is a classic drug used to prevent respiratory syncytial virus(RSV).Its application is limited due to its high price.In this study,a Chinese hamster ovary cell line(CHO cells)was engineered to produce palivizumab biosimilars.The key parameters of cell culture were optimized by response surface methodology,and media combinations were screened to increase yield.The results showed that a 16-days cell culture process using AM01-AF02 medium as the basal-feed combination,seeding at 5.0× 106 cells per milliliter,and temperature shift from 37 ℃ to 33.0 ℃ on day 7 improved palivizumab production by 69.3％in shake flask and 30.0％in 3 L bioreactor.The purification process at a 3 L bioreactor scale was also studied,which provided a reference for the subsequent process development of palivizumab biosimilars.