An apparatus for memory sharing between an interleaver and a deinterleaver in a turbo decoder is disclosed. A memory writes therein data obtained by interleaving data decoded by a decoder and writes therein data obtained by deinterleaving the data decoded by the decoder, in response to a control signal. A controller reads the stored interleaved data for a delay time of the decoder, generates a first control signal for writing the interleaved signal in the memory after a lapse of the delay time, writes the deinterleaved data in the memory for the delay time, and generates a second control signal for reading the stored deinterleaved data after a lapse of the delay time.