中文摘要：

简述脉冲星发现和计时观测的概况。文中概述脉冲星计时的物理模型和计算用的各种钦件,特别是全球广泛应用的TEMPO2软件,并描述脉冲星计时阵的概念和国际脉冲星计时阵。对脉冲星计时观测应用：建立脉冲星时标、改进行星历表（包括外行星质量测定和海外天体的发现）、检测引力波、测定脉冲星的旋转和天体测量参数、脉冲星自主导航、相对论引力理论的验证等作了介绍。最后,对我国开展此项工作的情况给予简要描述,并提出若干建议。

英文摘要：

The discovery of pulsar and timing observations are briefly described. The physical models of timing for pulsar and various softwares for pulsar timing, especially the TEMPO2 used worldwide, are mentioned in detail. The idea of pulsar timing array and international pulsar timing array are introduced. Pulsar timing is applied in the following aspects： developing a pulsar-based timescale, improving the solar ephemeris（including the determination of mass of outer planets and discovery of trans-Neptunian object）, searching for gravitational waves, determination of rotation and astrometric parameters for pulsar,autonomous spacecraft navigation with pulsars, tests of relativistic gravity and so on. Finally, the research work on pulsar timing technique and its application in China is simply introduced, and some suggestions are proposed.