Benefit of cropland conversion program and its evaluation in western China

On base of defining the concept of the benefit of cropland conversion project, this paper pointed out that ecological benefit is the most important aim of such project, while the unification and harmonization of economic and social benefit must be chased under this premise. There are two approaches in the evaluation of such project, one is ecological system services evaluation, and the other is the integrated evaluation. The former can offers an economical review of the investment and output of conversion project, and provides scientific base for the making of national economical policies, while the later can offers technical support for program selection before the project, problem dissolution and policy adjustment in the carrying out of project, effect evaluation after the pro- ject.