A chainless electric bicycle comprising: a motor to rotate a rear wheel of the chainless electric bicycle by means of the motor; a battery for storing electric energy and for supplying electric energy to the motor; a direction sensor to sense a rotation direction of pedals; a pedal load controller to adjust load applied to the pedals; and an electronic control unit to release the load applied to the pedals through the pedal load controller when the sensed rotation direction is a reverse direction and to apply the load to the pedals when the sensed rotation direction is a normal direction, characterized in that the pedal load controller comprises: a generator to generate AC power in accordance with driving of the pedals to charge the battery; a rectifier to rectify the AC power generated from the generator into DC power; a smoothing circuit to charge the DC power output from the rectifier so as to smooth the output power; and a switch connected in series between the generator and the battery to be charged with the power smoothed by the smoothing circuit, wherein the pedal load controller is configured to adjust the pedal load of the pedals by adjusting the amount of electric power charged in the battery after being generated from the generator in accordance with driving of the pedals; wherein the electronic control unit performs pulse width modulation control to turn on or off the switch when the sensed rotation direction of the pedals is a normal direction, to charge the battery with the power generated from a generator, wherein the electronic control unit turns off the switch when the sensed rotation direction of the pedals is a reverse direction, to open output terminals of the generator. a motor to rotate a rear wheel of the chainless electric bicycle by means of the motor; a battery for storing electric energy and for supplying electric energy to the motor; a direction sensor to sense a rotation direction of pedals; a pedal load controller to adjust load applied to the pedals; and an electronic control unit to release the load applied to the pedals through the pedal load controller when the sensed rotation direction is a reverse direction and to apply the load to the pedals when the sensed rotation direction is a normal direction, characterized in that the pedal load controller comprises: a generator to generate AC power in accordance with driving of the pedals to charge the battery; a rectifier to rectify the AC power generated from the generator into DC power; a smoothing circuit to charge the DC power output from the rectifier so as to smooth the output power; and a switch connected in series between the generator and the battery to be charged with the power smoothed by the smoothing circuit, wherein the pedal load controller is configured to adjust the pedal load of the pedals by adjusting the amount of electric power charged in the battery after being generated from the generator in accordance with driving of the pedals; wherein the electronic control unit performs pulse width modulation control to turn on or off the switch when the sensed rotation direction of the pedals is a normal direction, to charge the battery with the power generated from a generator, wherein the electronic control unit turns off the switch when the sensed rotation direction of the pedals is a reverse direction, to open output terminals of the generator. a generator to generate AC power in accordance with driving of the pedals to charge the battery; a rectifier to rectify the AC power generated from the generator into DC power; a smoothing circuit to charge the DC power output from the rectifier so as to smooth the output power; and a switch connected in series between the generator and the battery to be charged with the power smoothed by the smoothing circuit, wherein the pedal load controller is configured to adjust the pedal load of the pedals by adjusting the amount of electric power charged in the battery after being generated from the generator in accordance with driving of the pedals; wherein the electronic control unit performs pulse width modulation control to turn on or off the switch when the sensed rotation direction of the pedals is a normal direction, to charge the battery with the power generated from a generator, wherein the electronic control unit turns off the switch when the sensed rotation direction of the pedals is a reverse direction, to open output terminals of the generator.