Abstract: The power of single EO detector is limited, so EO netting is used to improve the overcast power in airspace and time domain. In order to improve the detecting probability and ability of EO netting to against the attacting target, an optimal dispostion method based on genetic algorithm（GA） was presented for EO netting. A mathematical model was established for optimal disposition to getting the maximal overcast region, then the optimal disposition scheme and the coordinates of EO detectors in the netting were afforded by using the genetic algorithm. At last, the optimal disposition scheme and the figures of the detecting overcast region for 4 kinds of targets were given by Matlab simulation, and the maximal overcast region fmax was 0.681 after 60 times of iteration. The feasibility of the proposed method was proved.