A method and apparatus for modulating pitch and identifying gender of a voice signal is provided. The voice modulation apparatus includes an LPC analyzer for obtaining vocal track filter coefficients reflecting characteristics of an input voice signal, a pitch detector for detecting the pitch and the gender of the voice signal, a pitch modulator for modulating the voice signal by applying a predetermined value to a detected value from the pitch detector, and a coder for coding the input signal from to LPC analyzer and to pitch modulator, and for outputting a coded signal.