Abstract: The work in this paper investigates the automatic extraction method of foreground areas in video sequences of a dynamic scene. In the method we proposed, firstly, a robust global motion estimation algorithm is proposed with ability to filter outliers adaptively. By estimating the global motion parameters and filtering the outliers alternately, the noise is restrained and the background is aligned accurately. To overcome the shortcoming of setting the value of the background noise variance by experience, we estimate the value by histogram fitting. Then, we use the significance test to threshold the difference image and extract the foreground areas. Experiments demonstrate that our method can align the backgrounds in successive frames and extract the foreground areas effectively.