Abstract: There is more than one local optimum in multi-modal landscapes. The values of local optima can influence their opportunities to be exploited by GAs. By analyzing the infinite population dynamical system using the gene pool GA and the BINEEDLE fitness function, we characterize the analytic relation between the fall of local optima and the fixed points in the infinite population dynamical system of the gene pool GA. Further analysis shows that the relation is still held in more common cases. Enlightened by the result, we derive a method to improve GAs for the multi-modal landscapes and get satisfying effect. The experiment results also prove the correctness of the theory in this paper.