From the perspective of ontology,the professional ability of ideological and political science teachers is the competence for professional tasks formed in their professional practice. It has the characteristics of professionalism,practicality,integration and de- velopment,and it is composed of teaching ability,scientific research ability,discipline construction ability and social service ability. From the perspective of generative dimension,it is formed under the interaction of endogenous and exogenous forces on the basis of ide- als and beliefs,professional knowledge,vocational skills and business capabilities,and represents the sustainable development process of nominal ability,functional ability,process ability and comprehensive ability. From the realistic dimension,there are some difficul- ties,such as insufficient endogenous motivation,weak foundation of generation,unbalanced structural system and limited level jump. From the practical dimension,meet the material and spiritual needs of ideological and political teacher and enhance endogenous motiva- tion; Strengthen the systematization of cultivation and training,and lay a pragmatic professional foundation; Set up multiple evaluation mechanism and practice platform,perfect the structural system; improving the hardware and software of hierarchical development and promoting the upgrading of vocational ability level are the paths of vocational ability improvement.