The compression of the GPS trajectories in a conventional way is greatly different with the original one for ignoring the speed information, the direction of GPS points and the shape of tracks. In this paper, we focus on saving the speed, the direction information and shape features of tracks on the premise of keeping the compression ratio. The Algorithm in this article is based on the road network information, OW(Opening Window) algorithm, the core point algorithm and the stay point algorithm, then presents a online compression algorithm which is capable of saving the temporal characteristics of GPS tracks. Experimental results show that the compression algorithm compareing to the existing compression algorithms, ensurs the compression ratio while improving to retain the temporal characteristics of the track.