Region of Interest (ROI) coding belong to the efficient region-based image compression method and is an important feature of JPEG2000 standard. In this paper, a new ROI coding method is proposed. In the method, we utilize the improved SPECK algorithm instead of EBCOT coding recommended by JPEG2000 to encode all scaled coefficients of ROI and BG. Because coefficient clustering and single quadtree partitioning scheme is applied, the presented method has the low computational complexity. Experimental results show that the new method cannot only efficiently encode these bitplanes shifted by Maxshift method or the general scaling based method, but also obtains lower algorithm complexity than these methods using EBCOT in JPEG2000.