Abstract: Objective　To evaluate the role of serum IgM, IgG and IgA anticardiolipin antibody (ACA) isotypes in the diagnosis of systemic lupus erythematosus (SLE), and their association with lupus nephritis (LN) in children. Methods  One hundred and sixteen hospitalized SLE pediatric patients were selected between April 2005 and October 2013. The clinical data were collected and analyzed. Results  There were 20 males and 96 females among 116 SLE patients. The positive rate of ACA-IgG, ACA-IgM and ACA-IgA was 37.1%, 35.3%, 26.7% respectively, without significant difference between each other (P>0.05). Among 116 SLE patients, 75 cases had LN and 41 cases had no LN. The positive rates of ACA-IgM and ACA-IgA were not significantly different between cases with and without LN (P>0.05). Cases with LN (42.7%) had higher ACA-IgG positive rate than cases without LN (22.0%) (P=0.026). The occurrence of LN and the positive rate of ACA isotypes were not significantly different between genders (P>0.05). Conclusions  The different isotypes of ACA have the same significance in the diagnosis of SLE. The detection of ACA-IgG helps diagnose the LN complicated with SLE.