In this paper, we proposed a real-time road boundary detection method in com-plex urban road environment. The detec-tion difficulty lies in road wear, both exis-tence of marked and unmarked boundary and low-resolution vision. The idea of the algorithm is to extract the road surface firstly using improved region growing method based on edge enhancement. The road boundary is then estimated by fitting the edges of the extracted road surface. A Bezier splines algorithm with optimiza-tion of control points is proposed to esti-mate the road boundary. The algorithm is implemented on the video collected in BEIJING urban streets and achieves good performance.