摘  要：引力无处不在，却又看不见，摸不着。人类最早从天体运动中接触到引力，并由此逐渐深入。其中最为重要的引力理论是牛顿引力理论和爱因斯坦引力理论，前者首次揭开了行星运动之谜，使人类第一次认识了宇宙，后者则更接近引力的本质，预言了一系列引力效应。本文为材料综述类文章，对牛顿引力理论，爱因斯坦广义相对论，以及二十世纪中后期的引力理论做了系统概括，对引力场，引力波，量子引力等方面做了总结，以期望给读者对认识引力的概念提供帮助。

关键词：引力，引力理论，牛顿，爱因斯坦，广义相对论，量子引力

Abstract: Gravity is everywhere, but it can not be seen and can not be touched. Humans understand the concept of gravity firstly from the movement of celestial bodies, since then people gradually research the concept.  The most important theories of gravity is Newton gravitational theory and Einstein gravitational theory, the former first unveiled the movement of the planets, making human first met the  mysteries  of universe, the latter is more closer to the essence of gravity and predicts the series of gravitational effects. This paper reviews materials about gravity, making a summary for Newton and Einstein gravitational theory, and theory of gravity of the 20th centaury. And it also involves Gravitational field, Gravitational waves and Quantum gravity .It is expected to give readers help to understand the concept of gravity.

Keywords: gravity, gravitational theory, Newton, Einstein, General relativity, Quantum gravity