Abstract： Objective To investigate the changes of panel reaction antibody (PRA) and the effects of HLA sensitized paths in patients waiting for renal transplantation.Methods PRA of 10 555 samples from 8926 renal transplant recipients in 51 transplant centers was analyzed.In 1991-1998 group,PRA was by using NIH-CDC technique,and in 1999-2010 group,PRA was detected by using ELISA.The effects of blood transfusion,pregnancy and transplantation on the PRA positive rate were analyzed.Results There were 1324 recipients positive for PRA in 8926 (14.83 ％ ).The average PRA positive rate in 1991 1998 group and 1999-2010 group was 18.17％ (513/2823) and 13.29％ (811/6103) repectively (P＜0.01).Among 1324 PRA positive recipients,the number of recipients with PRA of 1％-30％ and PRA of ≥30％ respectively accounted for 71.83％ and 28.17％.There were statistically significant differences in the PRA positive rate between the recipients receiving blood transfusion and those without blood transfusion (31.77％ vs 1.21％,P ＜ 0.01 ),between the recipients having pregnancy history and those without pregnancy history (24.64％ vs 7.19％,P＜ 0.01 ),and between primary transplant and re-transplant recipients (13.35 ％ vs 40.62％,P＜0.01).Conclusion In last 20 years, PRA in majority of PRA positive recipients was ＜ 30％ (low sensitized).Renal transplantation and blood transfusion were the important influencing factors that led to positive PRA,and pregnancy history was a related factor.