Objective To explore the early differential diagnosis significance of soluble receptor CD 163 in system onset juvenile idiopathic arthritis.Methods 33 children diagnosed with SoJIA in active period in our hospital from January 2010 to January were collected as the research group,40 healthy children for medical examination in the same period were collected as the control group,the operation flow cytometry method was used to determine the T cells,ELISA method was adopt for determining the level of serum CD 163.CD 163 expression level with disease activity index and the correlation were observed in the two groups.