Abstract: In most textbooks of “mechanics of materials”, the concentrated force is regarded as the force acting on a point when analyzing the shear force in beams, without discussions on the shear force at the point. To analyze this problem simply, the equivalent force systems method is adopted in this paper. The concentrated force is replaced with a distributed load that is symmetrical about the cross-section of action. It draws a conclusion closer to the actual situation: the shear force around that section changes continuously and its value can be determined theoretically.