Improvements are made to ViBe (Visual Background extractor) algorithm for enhancing its test effect and test speed.The algorithm utilizes several pixel values from consecutive frames to train and construct the final samples of background during initialization, thus to decrease the ghosts effects on precision in detecting an object and partially remove the noises on the edge of background objects.In the process of pixel matching, a classified threshold and a match threshold for scene complexity of the pixel are adjusted dynamically to adapt complicated background scenes and diminish the disturbances of incorrect foreground pixels.In order to reinforce the robustness of the improved algorithm, an adaptive time-subsampling factor is utilized to accelerate elimination of the ghost caused by the departure of background objects and recovery of the background samples.Experiments show that the algorithm presented here can remove the ghost and noises effectively and is appropriate for complicated background scenes detections.