Objective To detect de novo development of anti-HLA antibodies after renal transplantation, and to investigate their influence on graft function. Methods 384 kidney recipients,who were negative for anti-HLA antibody before transplantation, were monitored for anti-HLA antibodies over a period of 3-96 months, and a sensitive enzyme-linked immunosorbent assay (ELISA) was used to detect anti-HLA antibodies. HLA antibody ＞10 % was defined as positive levels. Results Among 384 recipients tested, 318 recipients (82. 8 %) were negative for anti-HLA antibody after transplantation; 66 recipients (17. 2 %) developed de novo HLA antibodies, 3 recipients with HLA class Ⅰ, 61 with HLA class Ⅱ, 2 with both HLA class Ⅰ and Ⅱ. According to amino acid residue matching, 7 cases developed de novo antibodies among 92 recipients with 0 HLA-DR mismatches,compared with 59 cases among 292 recipients with 1-2 mismatches, which showed significant difference between two groups (P＜0. 01 ). 87. 4 % (278/318) recipients negative for HLA antibodies after transplantation achieved good graft function, in comparison with 65. 2 % (43/66) recipients positive for HLA antibodies (P＜0. 05). Conclusion De novo production of HLA antibodies posttransplantation may be closely associated with HLA-DR mismatch. De novo HLA antibodies posttransplantation might damage graft function and reduce graft survival rate. The detection of de novo development of anti-HLA antibodies after renal transplantation has clinical significance for assessing renal allograft function.