Abstract: Centripetal force is an important concept in mechanics. By considering the understanding of centripetal force in three different historical periods, this paper clearly shows that the centripetal force has undergone a tortuous but deepening process along with people^,s understanding of basic motion and mechanical laws. It is shown that the concept of centripetal force as a bridge emphasizes its important role in the development of kinematics to dynamics. In particular, the development of the concept of centrifugal force to centripetal force is a revolutionary breakthrough, which promotes the establishment of the three laws of mechanics under the inertial system, and is a key step for Newton to discover the law of universal gravitation. 

Key words:  centripetal force, centrifugal force, Newton, Huygens, Kepler^,s three laws