Inhibitory ability of children with developmental dyscalculia (DD) was investigated to explore the cognitive mechanism underlying DD.According to the definition of developmental dyscalculia,19 children with DD-only and 10 children with DD&RD (DD combined with reading disability) were selected step by step,children in two control groups were matched with children in case groups by gender and age,and the match ratio was 1∶1.Psychological testing software named DMDX was used to measure inhibitory ability of the subjects.The differences of reaction time in number Stroop tasks and differences of accuracy in incongruent condition of color-word Stroop tasks and object inhibition tasks between DD-only children and their controls reached significant levels (P＜0.05),and the differences of reaction time in number Stroop tasks between dyscalculic and normal children did not disappear after controlling the non-executive components.The difference of accuracy in color-word incongruent tasks between children with DD&RD and normal children reached significant levels (P＜0.05).Children with DD-only confronted with general inhibitory deficits,while children with DD&RD confronted with word inhibitory deficits only.