Sustainable development that the system of human being and nature system(including resource and environment) evolve together, is a compound system, comprised by three subsystem: nature system(including resource and environment),economic and society(including population). Starting off the broad sense concept of resource, the three subsystems of nature, economic and social resources had been quantified as nature resource population loading capacity, economic resource population loading capacity and social resource population loading capacity. Based on which, the paper constructed sustainable development evaluation index system based on the resources loading, and analyzed the development level, the sustainable level, the sustainable development ability and its changes in the Pearl River Delta. In order to provide the reference to the similarity of the Pearl River, the thesis drew up the conclusion: ①In 2002, the contribution of the Pearl River Delta economic subsystem to the whole area had reached 55.6%, the index of development level had reached 2.71, that had advanced 0.01than the index of development level in 1998, which had entered the stage of the economic resources driving.②In 2002, the Pearl River Delta sustainable development index had reached 2.16, had heightened 0.09 than the sustainable development index in 1998. Social sub-system of the system was lagged behind its nature sub-system, economic sub-system of the system. ③ In 2002, the Pearl River Delta sustainable development capacity was placed in middling level of sustainable development, which has advanced 0.04 than the index of sustainable development capacity. ④In 2002, economic resource loading capacity was great. From the loading capacity of each subsystem, the economic resource loading capacity was largest among the whole Pearl River Delta, which is 31000 thousand people. Nature resource loading capacity is the second large, which got to 21000 thousand people. Social resource loading capacity was the third, which got to 9000 thousand, less 10000 thousand people than the sati in 1998. The whole Pearl River resource loading capacity was 56000 thousand people.⑤The trend of the Pearl River Delta sustainable development changing was obvious. In the light of level of sustainable development, the level of sustainable development of the nine cities in the Pearl River fluctuated very small extent, which means that sustainable development level is a comparative stable index. In the light of the level of sustainable, the whole Pearl River Delta sustainable level fluctuated in very small extent during 6 years, but sustainable of each city fluctuated in a big extent, which means that the level of sustainable is a index that related with development fettle in different parts. The level of sustainable development determined the change of sustainable development capacity in different area. In the light of sustainable development capacity, the sustainable development capacity of the nine cities had been changing obviously during past 6 years. Guangzhou, Shenzhen, Foshan, Huizhou, Dongguan, and Zhongshan's sustainable development capacity was rising; Zhuhai and Zhaoqing's sustainable development capacity was descending.