This study observes the sound changes of the Southern Min dialects of Little Liuchiu and Green Island with a vocabulary chart survey. The participants are 31 Little Liuchiu residents and 30 of Green Island, categorized by age into young, middle-aged, and older ones. The following are the three main points of the discussion. (1) The word groups〈雞〉[e],〈魚〉[i], and〈恩〉[in] in the dialects of the two islands are pronounced differently from those in the Chuan-based Southern Min dialects of Taiwan Island. This feature does not result from the increasing Taiwanese tourists visiting these two islands in recent years. (2) The dialects of the two islands have the same variants as the Chuan-based dialects for the〈青〉and〈買〉word groups. The older residents of Little Liuchiu predominantly hold the /dz/ initials whereas the /l/ initials are more common in Green Island. As for tone sandhi, the Green Island dialect keeps lots of /21/ rising tones as the Chuan-based Southern Min dialects while those in the Little Liuchiu dialect have completely changed to [33]. (3) This study analyzes the internal linguistic factors and language contact in the sound changes of the Southern Min dialects of the two islands. The emerging consonant [l] in the〈認〉word groups in Green Island can be attributed to internal factors. The preservation of the consonant [dz] in the〈認〉word groups in Little Liuchiu serves as a special local characteristic. The constant change of rising tones in the Little Liuchiu dialect into [33] exemplifies an interaction of internal linguistic factors and language contact