Tong–Tai (Chinese: 通泰), also known as Tai–Ru (Chinese: 泰如), is a group of Lower Yangtze Mandarin dialects spoken in the east-central part of Jiangsu province in the prefecture-level cities of Nantong (formerly Tongzhou) and Taizhou. The alternative name refers to the county-level city of Rugao within Nantong. This region includes the areas which are to the north of Yangtze River and to the east of Grand Canal. There are about 11.37 million speakers there (in 2004) and this region occupies about 15,000 square kilometers.

This region can also be divided further into three districts: the west, the middle and the east. The west part includes Taizhou, Jiangyan, west of Hai'an, west of Dongtai, Dafeng, Xinghua, east of Jiangdu. The middle part includes Rugao, Rudong, Taixing, east of Dongtai, east of Hai'an and southwest of Jingjiang. The east part includes downtown of Nantong and southwest of Tongzhou. These vernaculars are distinguished by the difference in consonants.

However these districts used to be the region of the Wu culture, so there are many features of Wu Chinese in these vernaculars, especially the vernacular in the middle part, known as middle Tong-Tai dialect. It is closely bounded on the Changzhou part in the Wu region.

The Nantong variety will be taken as representative.

r-colored ɜ: ɜ˞

tongue position for [ø] is slightly higher than the standard [ø], but lower than [y]

[ɛ] is slightly lower than the standard [ɛ], sounds close to [æ]

[ʌ] is higher than the standard [ʌ], close to [ɜ]