The sharedaperture thinned interleaved arrays design technology is an important infrastructure of integrated sensor system (ISS).It can reduce the quantity of antennassave spaceand reduce the loads and manufacture costs.The shared aperture interleaved arrays based on difference sets usually have high sidelobe levelsbecause of the asymmetric distribution of the thinned subarrays elements.A method of optimized interleaved arrays was proposed based on difference sets and genetic algorithm.Firstthe difference sets were used to determine the position of array elementsand the current magnitude distribution of arrays was taken as the decisionmaking variable.The genetic algorithm was used to lower the maximum sidelobe levelthus to improve the performance of the whole shared aperture interleaved arrays.The simulation results show that the method is effective to restrain the sidelobe levels and useful for interleaved array optimization.