It belongs to the Oujiang sub-group of Wu Chinese dialects.
Rui'an has the following finals: 嘸 [m], 兒 [ŋ] 姹 [a], 好 [ɛ], 包 [ɔ] 海 [e̝], 先 [i], 思 [ɿ] 下 [o̝], 布 [ʉ] ~ 圖 [ɘʉ] ~ 水 [ʮ] 全 [y], 安 [ø], 歌 [ʋ̩ʷ] 會 [ɐi], 走 [ɐu̜] 李 [ei], 六 [əu̜] 涼 [iɛ], 關 [uɔ], 花 [uo̝] 經 [ɐŋ], 聽 [əŋ], 公 [oŋ].
Additional finals for older accents include 天 [ie̝], 橋 [yø], 頭 [iəu̜] In the Ruian dialect, a monosyllabic word can have one of the eight tones, but there are only four phonetically distinguished tones, divided into high (陰) and low (陽) categories.
Yin Ping 陰平 [˦] 44 江天飛三 Yang Ping 陽平 [˧˩] 31 來同魚球 Yin Shang 陰上 [˧˥] 35 懂紙古本 Yang Shang 陽上 [˨˦] 24 近淡厚似 Yin Qu 陰去 [˥˨] 52 對去貨歲 Yang Qu 陽去 [˨] 22 外地路住 Yin Ru 陰入 [˧˨˧] 323 七博塔各 Yang Ru 陽入 [˨˩˨] 212 六肉白石 In bisyllabic words, the Rui'an dialect phonetically has only six tones, high flat ˦, middle flat ˧, rising ˨˦, departing ˦˨, entering ˨˩˨ and short ˨.
Below is a list of the most common vocabulary in Ruian dialect.