Abstract: A flight path planning method for general aviation using probabilistic weather forecast is proposed to solve the problem that the benefit of the flight path planned through deterministic weather forecast is low when the real weather condition is inconsistent with the forecast. The probabilistic weather forecast generated by ensemble numerical weather forecast is utilized to establish a probabilistic weather airspace model in the proposed method. Then a phased flight path planning is used to guarantee the expected requirement. The flight path planning is divided into several phases. Two different flight paths are planned from each start point in each phase except the first phase. One is the path completely avoiding risk regions and the other is the path crossing possible dangerous weather regions. The different paths in each phase are planned utilizing A* algorithm. Finally, an ensemble planned flight path containing several path is obtained. The experiment results using real probabilistic weather forecast data and simulated random probabilistic weather forecast data indicate that the statistical expected flight distance of the flight path obtained by proposed method is significantly shorter compared with other typical methods on the premise of ensuring safety.