To investigate the changes of serum osteocalcin in patients with rheumatoid arthritis (RA) in different gender and age, and the correlation with laboratory indexes of RA patients.Methods Blood samples and laboratory parameters of 324 RA patients (Divided into two groups of RA (M, F) by gender, and three groups of RA·Y, M, O by age) and 297 healthy controls (HC, Similarly, according to the above grouping, they are divided into two groups: HC (M, F) and HC·Y, M, O) were collected.The expression of SOST in plasma was detected by enzyme linked immunosorbent assay (ELISA).SPSS17.0 statistical software was used for analysis.Wilcoxon rank sum test and oneway ANOVA were used for comparison among measurement data groups.Spearman correlation analysis was used for correlation between variables.Results The levels of SOST, ESR, CRP, RF and A-CCP in RA group were higher than those in HC group (P＜0.05).The above indicators in the RA (M, F) group were higher than those in the HC (M, F) group (P＜0.05), and the serum SOST expression levels in the HC (M) and RA (M) groups were higher than those in the HC (F) and RA (F) groups, respectively (P＜0.05).The serum expression level of SOST in RA·M, O groups was higher than that in HC·Y, M, O groups, and RA·Y groups, while the serum expression level of SOST in RA·O group was higher than that in RA·M group (P＜0.05).The serum expression level of SOST in HC·M, O, and RA·Y groups was higher than that in HC · Y group (P＜0.05), the serum expression level of HC·O group was higher than that in HC·M, and RA·Y groups (P＜0.05), and the levels of ESR, CRP, RF, A-CCP in RA·Y, M, and O groups were higher than those in HC·Y, M, and O groups (P＜0.05).The levels of ESR and CRP in the group were lower than RA·M, O Groups (all P＜0.05).Spearman correlation analysis showed that there was a positive correlation between SOST and age in RA, RA (M), RA (F), RA·Y, RA·M and RA·O groups.There was a positive correlation between SOST and ESR and CRP in RA and RA (M) groups.Conclusion The expression level of SOST in serum of RA patients is significantly increased, and there are differences between different genders and ages, and it is positively correlated with age and inflammatory indexes, suggesting that SOST may participate in the occurrence and development of RA and regulate its inflammatory response