Objective：To provide the method and standard for measuring psychomotor ability and to estimate the prevalence of subcretins. Methods：JPB includes seven subtests. Stratified sampling was used according to population distribution in six districts in China. Results：The normal samples selected from 16 provinces were composed of 1 690 children living in urban and 1 742 in rural areas. These children were divided into 8 groups aged 7～14 years and the gender ration was 1:1. Reliability and validity were calculatd and the coefficients of retest reliability reached 0.45 to 0.96 4 months later. The cumulative contribution rate reached 67.8%. A four factors model was established based on varmax likelyhood and varmax rotation method. The raw scores increased at successive ages with significant difference (P<0.05). Some of the clinical reports proved that JPB had good discrimination. Conclusion：JPB is a satisfactory tool for measuring psychomotor ability. It can be applied not only in subcretin, but can also be used to detect brain damage.