Objective To investigate the changes of anti-cyclic citrullinated peptide antibody ,rheumatoid factor (RF) ,erythrocyte sedimentation rate(ESR) and C reactive protein(CRP) levels in the patients with early rheumatoid arthritis (RA) and their applica-tion value in the diagnosis and treatment.Methods A total of 210 cases of early RA in sixth affiliated hospital of Guangzhou Medi-cal University from December 2015 to June 2016 were selected as the RA group ,including 28 males and 182 females ,at the same time 115 cases of other rheumatism were selected as the non-RA group ,male ,including 38 males and 77 females.85 persons under-going the healthy physical examination were taken as the health group ,including 46 males and 39 females.The latex enhanced im-mune turbidimetry was adopted to quantitatively detect anti-cyclic citrullinated peptide antibody.The RF and CRP levels were quan-titatively detected by using the immune turbidimetry.The Westergren method was used to test the ESR ,their content changes in RA ,non-RA arthritis and other autoimmune diseases were detected.Results The sensitivity ,specificity ,positive predictive value , negative predictive value and Youden index of anti-cyclic citrullinated peptide antibody in the RA group were 60.95% ,97.64% , 98.46% ,50.30% and 0.59 respectively ,which of RF test were 52.38% ,95.29% ,96.49% ,44.75% and 0.48 respectively ,which of CRP test were 30.48% ,89.41% ,87.67% ,87.67% ,34.23% and 0.20 respectively ,which of ESR test were 49.52% ,87.06% , 90.43% ,41.11% and 0.37 respectively.Anti-cyclic citrullinated peptide antibody detection in the RA group was obviously higher than that of the RF test ,their test results were obviously higher than those of the non-RA group and healthy group ,the differences were statistically significant (P<0.05).CRP and ESR detection had no statistical difference between the RA group and non-RA group (P>0.05).Conclusion Anti-cyclic citrullinated peptide antibody level is higher in the patients with RA ,which is signifi-cantly superior to the RF test ,and anti-cyclic citrullinated peptide antibody detection has higher value for early diagnosis of RA.