Based on the reflexes of the Middle Chinese Cheng-initial in the three Hainan Min dialects of Haikou, Wencheng and Qionghai, this paper attempts to explain the “transplantation” and “adjustment” of language strata. Three main strata can be distinguished in the Hainan Min dialects. Interestingly enough, two of them show correspondences to the mainland Southern Min. This suggests that the proto-language of Hainan Min may not be homogeneous in nature, but rather contains two different strata instead. Another stratum was introduced to the Hainan Min after frequent contacts with Cantonese. The interactions among these three strata have led to several outcomes: (1) only new literary readings being preserved, (2) colloquial and literary readings still competiting with each other, (3) bidirectional diffusion, (4) only colloquial readings being preserved. In the final section of this paper, the author discusses how the phenomenon found in Hainan Min have enhanced our knowledge of language stratification.