PURPOSE: An orthogonal complex spreading device and method for a multi-channel are provided to maintain a ratio of peak power-to-average power in a low state, and to eliminate a phase dependency according to the interference of a self signal, generated by a POCQPSK(Permutated Orthogonal Complex Quadrature Phase Shift Keying)method based on an OCQPSK(Orthogonal Complex QPSK), and a signal generated by the reflection of the self signal in a multi-path, and the interference of the self signal and a signal of another user. CONSTITUTION: Complex multipliers(100-100n) multiply data of an optional one channel by a gain and a Hadamardas sequence, and multiply data of another channel by a gain and a Hadamardas sequence, for a complex-sum of the data of the two channels. One complex multiplier multiplies the complex-summed data by a complex format of an orthogonal Hadamardas sequence, for outputting, and data of two channels are complex-multiplied with the same manner. A summing unit(200) sums outputs of the complex multipliers(100-100n). A spreading unit(300) multiplies outputs of the summing unit(200) by an optional SC(Spreading Code), for spreading. A pulse shaping filter(400) filters data spread in the spreading unit(300). And a modulating carrier multiplier(500) multiplies outputs of the filter(400) by a modulating carrier, to output modulated data through an antenna.