A parabolic wave generator in a color television receiver or the like wherein, when the amplitude level of an input sawtooth wave is higher than the center level thereof, squared currents of mutually reverse polarities obtained by squaring the difference current proportional to the difference voltage between the two levels are added to each other at a predetermined rate, so that one side portion of a nonsymmetrical parabolic wave is produced. Meanwhile, when the amplitude level of the input sawtooth wave is lower than the center level thereof, squared currents of mutually reverse polarities obtained by squaring the difference current proportional to the difference voltage between the two levels are added to each other at another predetermined rate to thereby produce the other portion of the parabolic wave. Consequently it becomes possible to generate the two side portions of mutually different waveforms. And a desired nonsymmetrical parabolic wave can be achieved by combining such two side portions with each other through addition of the currents thereof without raising any problem in regard of the discontinuity or level difference that may otherwise be caused in the vicinity of the peak of the parabolic wave.