This paper analyzes the sound strata of the initials 從、邪、崇、船 and 禪 of Middle Chinese in Wu and Jianghuai Mandarin, and examines their properties with reference to related phenomena in the Beijing Mandarin and Min dialects. It then classifies the internal subgroups of Wu and Jianghuai based on the sound strata in these dialects. This research finds that subgrouping Chinese dialects based on sound strata can better reveal the evolution of these dialects, as well as any contact between them and how closely or distantly they are related.