The path planning of URAV must take multi-constraint satisfaction as prerequisite, otherwise, the path planned can only be an ideal one, and the application of the flight path will be undesirable. In this paper, a genetic algorithm for path planning of URAV was proposed. Considering the influence of multi-constraints, the genetic algorithm adopted the polar coordinates encoding method, which can embed the path planning constraints into the algorithm model. Adaptive mutation and crossover operators were applied. This method ensures that the URAV should arrive at the target with higher survivability. The simulation results show that this method is feasible and effective for path planning.