Abstract: The purpose of this study is to make a functional classification of the cities and towns in Sichuan, Yuannan, and Guizhou provinces in Southwestern China on the basis of the National Statistical Data of 1979, according to the method formulated by Howard J. Nelson in 1955,The rsult shows that,the correct way of using H.J. Nelson's method of quantitative analysis is to revise it by taking the actual conditions into account. The results of the functional classification are as follows. There are 18 multiple-functioned cities from the total 22 ones with administrative municipality; among them 3 are provincial capitals, 12 are prefectul centres and the other 3 are economic-cultural centres without political-administrative function over some administrative areas, Chungqing with a population of about 2 millions is one of this kind of economic-cultural centres, the biggest city in Southwestern China, another two are small cities with a population of around 200 thousands each. Moreover, there are 12 cities with distinctively specialized industries, such as metallurgy, coal mining, manufactures, textile, chemical,paper-making, salt-making, and sugar-making industries etc.The statistical data for the functional classification of the administrative towns and rural centres (district, commune or township centres under the county) are inadequate. The administrative towns are usually the prefectuml or county centres (but there are more than one half of the county centres withou town-administration in the three provinces),A few of them are district centres, or towns of prominent commercial-industrial, purely industrial, mining or suburban characters. The proportion of the labours in industry is small, about one-third of the total, but it is about one half in the cities with administrative municipality,Usually there are several dozens of rural centres in every county, but only one or two of them (including county centres) have town-administrative offices. The commercial function of the rural centres is more prominent than that of the administrative towns.