Abstract: A method of drosophila movement trajectory and courtship behaviorreappearance based on video processingis proposed to increase the manual detection efficiency of drosophila courtship behavior and track the drosophila movement trajectory more easily. After the image was segmented with Ostu algorithm, the drosophilas were located in circumscribed ellipses. Then shape characters(area, perimeter and roundness) and 7 moment invariant characters were achieved, and fake courtship drosophilaswere deleted according to positional relation and gray mean variance of the difference image, anddrosophila courtship behavior was recognized with the shape characters and moment invariant characters. Finally Kalman filter and feature matching method were used to predict drosophila movement trace. The experiment result shows that the method presented in this paper could recognize courtship behavior of drosophila and stalk moving drosophila accurately.