I engaged myself in the investigation of the phonetic system of Ju-kao dialect, for this dialect is my native language and I used it to talk with my parents in my family. This report was divided into two parts: The first part is a phonetic and phonological study of the dialect of Ju-kao. The second part is a comparative study of it with historical phonology, Wu dialect and Eastern Mandarin. Ju-kao is a district of the province of Chiang-su, and its dialect is spoken between the two large dialect groups of Wu and Eastern Mandarin. I hope to determine which group this dialect should belong to. On the basis of my pronounciation, I conclude that in the dialect of Ju-kao there are sixteen consonant phonemes, eight vowel phonemes and six tones as follows: Consonant phonemes: (The form abridges) Vowel phonemes: (The form abridges) Tones: 1.) The low level tone (」11). 2) The high rising tone (□35). 3) The high glide tone (□424). 4) The mid-high tone (□44). 5) The short mid-high tone (□44). 6) The short high rising tone (□35). From the above-mentioned comparative study, I determined this dialect belong to Wu dialect, and have some influence by Eastern Mandarin.