Suzhou Wu is one of the major Chinese varieties and represents the Wu culture. Many researchers have anecdotally noted ongoing sound change of its phonemic and tonal systems. However, the latest investigation remains Ye and Sheng's description (1996). Thus, this study conducted an acoustic analysis on how young (M = 21.63, SD = 0.92) and middle-aged (M = 46.75, SD = 3.77) native speakers produced monosyllables in Suzhou Wu. Four male and four female local Mandarin-Wu bilinguals from each age group (16 speakers in total) were recruited to read 97 Chinese characters covering all phonemes and the 7 tones in the previous Suzhou Wu inventories (Wang, 1987; Ye and Sheng, 1996). Results suggest that there are noticeable acoustic differences between the two age groups in terms of consonants (excluding the lateral approximant [l]), vowels (some monophthongs: [i, a, ã, ˀ], most diphthongs and triphthongs), the tonal patterns (tone 2: low rising, tone 3: high falling). These results not only indicate sound change of Suzhou Wu, but also provide evidence for the age-related divergence which might be attributed to its frequent contact with the official language (Mandarin).