Objective To investigate the expression of human platelet antibodies(HPA)in children with immune thrombocytopenia(ITP)at different ages and their clinical significance in the treatment of ITP.Methods Two hundred eighty-eight cases of children who were newly diagnosed as primary ITP and detected with HPA from January 2013 to December 2015 in the First Affiliated Hospital of Zhengzhou University were selected.According to the HPA values,they were divided into <1:10 group,1:10 group and >1:10 group.According to their age,they were di-vided into <3-year-old group and ≥3-year-old group.Data were organized and the relationship among platelet antibody,age,gender and short-term efficiency of treatment was analyzed by using SPSS 21.0 statistical analysis soft-ware.Results In this study,there were 288 cases of children,with male to female ratio of about 1.3:1.0.As to the<3-year-old group and ≥ 3-year-old group,this difference of male to female ratio was statistically significant (respectively 1.93:1.00 and 1.02:1.00,χ2=6.629,P<0.05),and the difference of the HPA positive rate was statistically significant(respectively 72.5% and 59.5%,χ2=5.716,P<0.05);the HPA positive rate of boys and girls respectively was 65.9% and 63.7%,so their diffe-rence of the HPA positive rate was not statistically significant (χ2=0.143,P>0.05).Regarding the short-term efficiency,HPA in <1: 10 group,1: 10 group and >1:10 group was respectively 89.1%,89.1%,100.0%.Statistical analysis suggests:the short-term efficiency of <1:10 group and 1:10 group was basically the same(χ2=0.000,P>0.05);In comparison of <1:10 group with >1:10 group(χ2=4.268,P<0.05),and in comparison of 1:10 group with >1:10 group(χ2=4.411,P<0.05),their differences were statistically significant.Conclusions This study suggests that boys are more susceptible to ITP,espe-cially in the <3 age group.The total positive rate of HPA is higher in <3 years old group.The HPA has a certain guiding significance for the diagnosis of ITP.Compared with the other 2 groups,HPA>1:10 group may have higher short-term efficiency in clinical practice.