Abstract: By viewing the optimum multiuser detector in code division multiple access communications systems as a combinational optimum problem, we apply the global optimum performance of genetic algorithms to design a kind of decorrelating multiuser detector based on parallel genetic algorithms(PGADEC-MUD). Theoretical analyses and numerical simulation results have shown that in aspect of multiple-access interference and near-far resistance, the PGADEC-MUD is better than the conventional detector and decorrelating multiuser detector and can be easily implemented by VLSI technology, which benefites from the parallel genetic algorithm.