Abstract: Dongchangfu County is a county of L. iaocheng Area of Shandong Province and an agriculture area of northChina and Huanghuaihai plain. It has large population and less developed economy, particularly rural economy isback ward. With the development of 50 years in the past, it had formed four characteristics of PRED system:firstly, gross population has large scale and is increasing rapidly but is less-educated; secondly, natural resourcessuch as mineral, water and energy are scare, land resourees are main natural resources but are poor and less pro-ductive; thirdly, natural disasters such as drought, flood, saltization and alkalization had been better preventedfrom, but some of themn still did great damages to the region; fourthly, with the rapid growth of economic, cap-ital and technology inputs are less sufficient, it consumes large resources with large waste.
According to the GM (1, 1) model and statistic materials from 1978 to 1996, the prediction models of culti-vated land, gross population, average cultivated land, agriculture population, regional GNP, water resourcesconsumption and demand of capital were established. It has formed four paradoxical relations with PRED sys-tem. The first, population increase rapidly but cultivated land decrease continually; The second, water resourcessupply can not cater for the demand; The third, large area of less productive land and can not satisfy the desireof people wanted to produce more; The fourth, the inputs of capital and technology can not satisfy the demandof the rapid economic growth. Based on these problems, some countermeasures to the sustainable agriculture areput forth : (1) optinizing the agricultural structure, mainly through adjusting the structure of planting; (2) promoting agriculture development by intensification, capitalization, marketing, business and factory; (3) in-creasing land resources productivity; (4) establish the adjusting controlling system for sustainable agriculture de-velopment.

Key words: PRED system, sustainable agriculture, Dongchangfu county