Objective To investigate the association between gene polymorphism of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and Graves ophthalmopathy (GO) in Qinghai Han population.Methods Ninety cases of Graves disease were selected from June 2011 to February 2014 in The People's Hospital of Qinghai Province,and the 90 patients were divided into two subgroups according to GO (49 cases) and GD without GO(41 cases).Then the genotype and allele of CTLA-4 exon 1 (+ 49A/G) were detected in surum by the method of polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP).Results The distribution of CTLA-4 exon 1 (+ 49 A/G) genotype frequencies (AA,AG,GG) was not different between GO and GD without GO subgroups [4.1％ (2/49) to 7.3％ (3/41),44.9％ (22/49) to 61.0％ (25/41),51.0％ (25/49) to 31.7％ (13/41),Fisher exact probability,P =0.180 ＞ 0.05]; the distribution of CTLA-4 exon 1 (+ 49A/G) allele frequencies (A,G) was not different between GO and GD without GO subgroups [26.5％ (26/98) to 37.8％ (31/82),73.5％ (72/98) to 62.2％ (51/ 82),x2 =2.622,P＞ 0.05].Conclusion CTLA-4 gene exon 1 (+ 49A/G) may not be a candidate susceptibility gene for Qinghai Han GO.