中文摘要：

基于各省城镇居民收入分组数据,通过拟合收入分布方法估计了2008-2012年间各省城镇基尼系数及总体城镇基尼系数。结果发现,城镇总体基尼系数呈现下降趋势,由2008年的0.3415下降到2012年的0.3154;其中,青海和重庆分别是5年间城镇基尼系数最大和最小的地区。按照基尼系数的完全分解框架,对城镇收入差距进行了按东、中、西地区分组的群体分解,结果表明,城镇收入差距绝大部分来自组内差距;东部地区的阶层效应最为明显,即与中、西部地区相比,东部地区更加趋向于形成一个阶层;进一步按收入分组的群体分解结果也同样表明,城镇收入差距绝大部分来自组内差距,高收入组群体更加趋向于形成一个阶层。而且,我国城镇居民收入分布的群体阶层效应越来越明显。

英文摘要：

Based on the urban residents＇ grouped income data of each province, this paper estimates the urban gini coefficient of each province and the total urban gini coefficient during2008-2012 with the method of fitting income distribution. The results show that the total urban gini coefficient is presenting a declining trend, from 0.3415 in 2008 to 0.3154 in 2012; in which, Qinghai and Chongqing hold the largest and smallest urban gini coefficient during the five years respectively.According to the complete decomposition frame, it conducts a group decompose of urban income gap in terms of the eastern, center and western regions. The results show that the urban income gap is mostly due to the in-group gap; the class effect of the eastern region is most significant, i.e., compared with the central and western regions, the eastern region all the more tends to form a stratum.The results of further group decomposition according to income also prove that urban income gap come mostly from the in-group gap, the higher income group even tends to form one stratum. What＇s more, the group class effect of China＇s urban residents＇ income distribution is becoming increasingly apparent.