Recently, the Workflow Management System (WFMS) becomes more and more popular, those that have existed can simulate flow logic of the business process, but cannot simulate business constraint.

So,in this paper,we introduce the concept of business constraint,create a model of business constraint,give a scheme to combine business constraint with flow logic,and present an implementation of business constraint in existing workflow management systems.

This paper advances five measures for developing the modern agriculture such as developing the intensive agriculture,developing the moderate-scale agriculture,developing the commodity agriculture,developing the circulating agriculture and improving the quality of peasants.

Theoretical Analysis and Empirical Study on the Transacting Behaviors of Contract Farming in China;