With the deepening of reform and opening up in China, people's income has been greatly improved. The second step of the "three steps"-people's life reached a well-off level at the end of the 20th century, which was also successfully realized at the end of the 20th century. We are now moving towards the third step. However, when we strive to reach the level of moderately developed countries in the middle of the next century, the gap between the rich and the poor in China is also widening. In China, the reasons for the widening gap between the rich and the poor are very complicated, including natural selection factors in the development of market economy, specific structural and institutional factors in the transition period, and abnormal factors such as corruption and market disorder. To correctly understand the income gap in China, we must have a good understanding of the types and causes of the income gap in China. At present, the income gap in China can be roughly divided into urban-rural gap, regional gap, industry gap and income inequality gap. The following mainly introduces the regional income gap in China, and analyzes the causes of this gap. First, the status quo of regional disparity The regional disparity of urban residents' income has further widened. The income level and growth rate of urban residents in the eastern region are significantly higher than those in the central and western regions, and the income gap is widening year by year. From 198 1 to 1999, the per capita income of urban residents in the eastern region increased by 15.0 1 times, in the central region by 12.2 times, in the western region by 9.5 times, and in the central region by/kloc-. The income ratio of the eastern, central and western regions changed from1981.20:1.80 to1.48:1. Changes in the regional disparity of urban residents' per capita income [1] In view of the widening gap between regions, some people generalize it as "one China, four worlds", that is, put China 3/kloc-0 provinces, municipalities and autonomous regions (except Taiwan Province Province) into the world to understand, and calculate the dollar value according to the actual purchasing power parity, which can be divided into four worlds: the first world is Shanghai and Beijing. From 65438 to 0999, the per capita GDP of Shanghai and Beijing were 155 16 and 9996 respectively, which were significantly higher than the average level of middle-income countries (US$ 8,320), and the population of Shanghai and Beijing accounted for 2.2% of the total population in China. The second world is large and medium-sized cities and upper-middle income areas in coastal areas. The per capita GDP of Tianjin, Guangdong, Zhejiang, Jiangsu, Fujian, Liaoning and other coastal provinces is higher than the average level of middle-income countries in the world (US$ 3,960), and the population of six provinces and cities accounts for 2 1.8% of the national population. The third world is a middle-lower income area, including Hebei, Northeast China and some coastal areas in central North China. Per capita GDP is lower than the average level of lower-middle income countries, and the population accounts for 26% of the total population. The fourth world includes poverty-stricken areas in the central and western regions, ethnic minority areas, rural areas, remote areas and low-income areas. It is lower than the average level of low-income countries in the world (US$ 65,438 +0.790), and its population is about 630 million, accounting for 50% of the total population of China.