分析了刚体在水平软支承面上做纯滚动和软物体在水平刚性支承面上做纯滚动两种情况下的滚动摩擦成因，分析表明滚动摩擦是一个物体在另一物体上滚动或有滚动趋势时，支承面对滚动物体作用力的不对称分布所引起的一种阻碍滚动的作用，并对滚动摩擦和滚动摩擦力的概念进行了阐释.

Rolling friction is very common in our real life, but most students lack a correct understanding of the cause of rolling friction. In this paper, the cause of rolling friction is analyzed in two cases: a rigid body on a horizontal soft underlay and a soft body on a horizontal rigid underlay. It is found that rolling friction is a kind of effect caused by the asymmetric distribution of the force applied to the rolling body that hinders rolling when one object is rolling on another object or has a rolling tendency. The concepts of rolling friction and the force of rolling friction are also explained.