Objective. To explore the role of HLA- DRBI genes in the development of rheumatoid arthritis（RA） and the orrelations between HLA-DR alleles and clinical manifestations of patients with RA.Methods. 86 patients with rheumatoid arthritis and 106 race matched controls were studied in whom HLA-DR typing was perfomed by the method of DNA amplification with sequence-specific primers（PCR-SSP）. The subtypes of HLA- DR4 were determined by the method of hybridization of PCR products with sequence- specific oligonucletides（PCR-SSO） . The absence or presence of HLA-DR4 and its subtypes was correlated with the clinical and serological characteristics of the patients.Results. Compared with controls

an increased gene frequency of HLA-DR4 （48. 8% vs 17. 9 %

P<0. 001） and a decreased frequency of HLADR7 （ 16. 3% vs 27. 4 %

P = 0. 06 ） were found. The DRB1.0405 account for 61. 9 % of DR4+RA patients and 21. 1% of DR4+ controls（P<0. 01 ）. There was no difference between the DR4+ and DR4- patients with respect to age

sex

duration of disease

rheumatoid factor （RF）

extra-articular manifestations including secondary Sjogren’ s syndrome. According to the wrist X- ray stage

the patients of DR4+ were more severe than that of DR4- （P<0. 05）.Conclusicon. HLA-DR4 and DR4 subtype of DRB1 0405 are related to the development of RA in Chinese. HLA-DR4 can be a useful prognostic marker in the patients with RA.