Abstract: For the bottleneck of improving the accuracy of minority class samples within the paradigm of imbalanced datasets,a novel under-sampling method based on the cooperative co-evolutionary mechanism was presented in this paper.During the employment of the method,the majority and the minority samples were divided into two populations,which adopted the cooperative co-evolutionary mechanism,dynamically adaptive crossovers and mutation operators to automatically adjust the evolution process within populations.Simulation results prove that the method enhances the capacity of local search,improves the distribution characteristics of populations and strengthens the capacity of global convergence.Moreover,the method notably improves the accuracy of the minority samples without degrading that of the majority ones.Compared to other classical resampling methods,the method shows good noise immunity with more powerful robustness.