The paper briefly elaborates the aims and objectives of National Science and Technology Library (NSTL), analyzes the current changes of information service environment and the challenges to NSTL, introduces the new service modes which are explored by NSTL as well as their effects and characteristics， points out the future development direction of NSTL service, namely, concentrating the power to guarantee the core resources, comprehensively realizing the open service mode, advancing knowledge service demonstration research, constructing joint and collaborative service mechanism.