中文摘要：

在经济快速发展和居民收入水平不断提高的同时,居民收入差距不断扩大,收入两极分化现象凸现。收入稳定的中等收入群体在社会发展中扮演着＂稳定器＂的角色,只有越来越多的人加入中等收入群体,才能体现改革开放带来的＂国强民富＂,体现收入分配的效率与公平。根据1992～2008年北京市城镇居民住户调查的微观数据,采用部分排序法,对中等收入群体比重进行测算。结果表明：从绝对量上看,北京市城镇中等收入群体的绝对数量偏少;从相对量上看,北京市城镇中等收入群体比重呈逐年下降趋势。说明无论从绝对量还是从比重上看,北京市还未形成中等收入群体占大多数的＂橄榄型＂收入分配格局。

英文摘要：

With the fast economic development and the improvement of resident income level,the income gap among residents enlarges and the phenomenon of income inequality becomes more and more prominent.Middle-level income groups with stable income plays the role of ＂stabilizer＂ in social development.Only if more and more people join into the middle-level income group,the ＂prosperity＂ brought by the opening up policy as well as the efficiency and equality of income distribution can be reflected.Based on the micro data of the survey of urban residents in Beijing from 1992 to 2008,the proportion of middle-level income groups is measured by using sorting method.Results show that the absolute quantity of middle-level income group is less than expected;from the angle of relative quantity,the proportion of the group gradually decreases year by year.This proves that from the perspectives of absolute quantity and proportion,the ＂olive＂ income distribution pattern with middle-level income group takes the majority has not been formed in Beijing.