Many questions regarding local economic phenomena involve issues of spatial and temporal dependence and heterogeneity. One of the main ideas of the socialist market economic system which was set up in 1978 in China is ‘those becoming rich earlier bring along other people, all achieving the common richer eventually’. However, after several decades, having performed a series of balanced development strategies and policies, is this purpose true or not? How about the outcome of regional level of planning strategies under the socialist‐market system? This paper focus on the intra provincial development, and uses per capita GDP of Guangdong, one of the most developed provinces in China to analyse the economic development of prefecture‐level cities from 1978 to 2013 with a new exploratory space‐time method. Three conclusions can be drawn as follows: first, the degree of regional economic development is gradually deepening along with rapid economic development in Guangdong province and the per capita GDP difference is gradually widening between the Pearl River Delta region and the non‐Pearl River Delta region. The core‐periphery relation is clear within the provincial level's development. Second, the trend and position of space‐time paths are different across regions. Third, the space‐time paths have not intersected across poor and rich regions during the last 33 years. Widening uneven development is concealed by the ‘fast growth’ economic phenomenon. The macro‐economic environment has had some effects on different regions, with the effect on fast growing areas, such as the core region of the Pearl River Delta the most obvious. There is a lag effect on other undeveloped areas. At the same time, under the socialist market economic system, the market is the main motivation behind regional discrepancies, and some policies and strategies aimed at narrowing the gap have had limited success.