A left and right feet pedaling analysis system is disclosed, comprising a pedaling sensing device and an electronic carrier, wherein the pedaling sensing device includes one or more transmission units and one or more accelerometers which are applied to detect the acceleration change data during pedaling, and the pedaling sensing device or/and the electronic carrier can analyze the signals coming from the accelerometer during riding the bicycle in order to acquire the pedaling rotation number, the ratio of the left and right foot forces as well as the installation direction thereby understanding the pedaling distribution ratio of the left and right foot when riding; as such, it can help improve the pedaling skills and adjust the pedaling force mode so as to reduce the risk of injury caused by excessively unbalanced pedaling asymmetry.