A motion aligned spatial scalable video coding scheme (MA-SSC) is proposed in this paper. Different from the traditional spatial scalable coding schemes derived from MPEG-2, in the proposed scheme only one set of intra or inter prediction modes are optimally selected by jointly considering the base and enhancement layers. Thus, it saves one set of macroblock (MB) mode and motion vectors. Moreover, the combined motion estimation can reduce the residual coding bits of the base layer. The MA-SSC and traditional spatial scalable coding schemes are both implemented based on H.264 reference software to evaluate their performance. Simulation results show that the enhancement layer coding efficiency of MA-SSC is up to 0.6dB better than that of the traditional scheme, while the base layer coding efficiency of MA-SSC decreases less than 0.3db compared with the single-layer coding.