POLARIZATION DEVELOPMENT OF THREE URBAN GROUPS IN NORTHEAST CHINA SINCE 1990
用基尼系数和KZ指数分析东北三省三大城市群内部及与其他城市的经济不平等和极化程度，发现其极化仅在东北内部显著，相对全国三大城市群并不突出。
There are three urban groups in Northeast China and they are the central-southern urban groups of Liaoning,the central urban groups of Jilin and the Harbin-Daqing-Qiqihar urban groups.Firstly,the economic state of three urban groups and their economic positions in Northeast China are analyzed.Secondly,the economic development inequality and polarization among three urban groups are quantitatively analyzed by Gini coefficient and KZ index based on GDP per capita.At the same time,the inequality and polarization between three urban groups and other cities in Northeast China are analyzed.The polarization development of three urban groups is divided into three phases:1990-1995,1996-1999,2000-2007.Thirdly,on the whole the three urban groups in Northeast China compared to the three urban groups in China: the Beijing-Tianjin-Hebei,the Yangtze River Delta,the Pearl River Delta.It is concluded that the development polarization of three urban groups in Northeast China is prominent only in Northeast China,but their development polarization isn’t distinct when they are relative to the Beijing-Tianjin-Hebei,the Yangtze River Delta,the Pearl River Delta in China.The economic positions of three urban groups in Northeast China are lower than them in China.In the end,the driving forces of development polarization of three urban groups in Northeast China are analyzed.