Abstract：Mask schemes are generally accepted as countermeasure methods in side channel analysis. Lightweight countermeasures became the development tendency facing the application of cryptographic chips. This paper extends the RSM scheme to the RSM-Like scheme that the mask bytes have the same Hamming weight. We propose several power analysis methods against the RSM and RSM-Like schemes, and we propose a power analysis method MCPA. Based on the principle of clustering the traces, MCPA only requires the cluster number of the mask bytes to break RSM-Like scheme successfully. This paper validates MCPA on the reference traces of DPA contest V4, and the clustering successful rate can reach nearly 100%. The MCPA could be regarded as a general analysis on the lightweight mask scheme and should be considered by the lightweight mask scheme designers.