Abstract: A method of measuring motion power and resistance coefficient of a bicycle measures sensed data including at least one front projecting area of a bicycle ridden by a user, an air temperature value, an air pressure value, a traveling speed value, an acceleration value, a relative wind speed value, an inclination value and a total weight value to calculate an air resistance coefficient, a rolling friction coefficient of a bicycle tire, a force and a motion power applied to the bicycle by the user, so that the user may learn a better riding posture for different riding conditions and reduce the air resistance effectively by adjusting the riding posture, so as to reduce the consumed motion power. Through the installation of a display unit, the user may know about the data sensed by the sensor and the computation result of the processing unit anytime.