Spatial polarization and uneven development has been the center of attention and of heated debate over the years.Much of the research is focused on the shifts of capital, jobs and population from the old industrial core to new cores or to the periphery.The theories of polarization and polarization reversal are central to regional development in advanced industrial economics.As for polarization, the most significant indicator is the emergence, consolidation and widening of gap between the economic core and economic periphery within a region or a country.Confronted with equipment obsolescence, unionized labors force and high production costs, the old industrial core has emerged polarization reversal.The theories of polarization and polarization reversal suggest that in the old industrial core the leading sector role of manufacturing has diminished in old manufacturing poles, and that income growth trends differ substantially between these old poles and new centers of development.In summary, based on the framework of polarization and polarization reversal, we can observe the spatial variation within the old industrial core, new growth center and periphery region.Since the economic reforms of 1978, China has opened up to foreign investment but retained restrictions on labor migration until the beginning of 1990s.In recent years, some impacts of these reform and open policies in regional development have been observed.It is significant that regional inequality is enlarged between coastal and inland regions but also between urban and rural regions in China.Guangdong Province is one of the first provinces in the People’s Republic of China to benefit from the open door policy which is representative in this research.Usually, the regional dynamics literature has tended to pay more attention to state or macro regional variation of growth than to regional or local variation.By taking Guangdong province as a case, this paper gives a method of measuring regional polarization and discusses the spatial polarization of growth within a region in order to give a clear explanation to the process of regional polarization under socialist market system.The consequence shows that regional polarization is a dynamic process under socialist market system, the core role may disappear when the leading sector of manufacturing declines.It is found that the old central cities, such as Guangzhou Shaoguan, Zhanjiang, Shantou and Chaoyang experienced a gradual process of weakening of their roles in regions, and some new cities, for example, Shenzhen, Zhuhai, Dongguan, Zhongshan, Shunde, Nanhai and Panyu became new regional growth centers.In general, the change of Guangdong’s regional structure can be described as a process of regional polarization.