Wu dialect, traditionally said Wu, also known as Zhejiang words or Jiangnan words, is China's oldest and second largest dialect。 "Wu" is the use of the ancient geographical name。 Wu dialect prevails in the southern parts of Jiangsu Province, northwest corner of Fujian, northeast parts of Shanghai, Zhejiang, Jiangxi and the south of Anhui, and about more than 110 counties with a population of about 77 million use it, accounting for 7。2% of the total population of the Han nationality。 According to the linguistic features, the internal differences of the Wu dialect are important, unlike the northern dialect, from the northeast to the southwest in a straight line distance of more than 3000 kilometers, from Harbin to Kunming, in which not only the voice system is relatively simple, but also the vocabulary is similar, even grammar is consistent。 And as one of the seven dialects of modern Chinese, Wu dialect has formed unique pronunciation characteristics in the long-term development。 According to the analysis from the perspective of phonetics, its general characteristics are: