Environmental evaluation and planning is a hot point of the relative science research nowadays. So the work is carried out in the Dingxi prefecture, a typical loess gully-hilly region of the semi-arid regions. The AHP method is used to evaluate the characteristic, quality, and degree and potential in use of the regional ecological environment. Then some suggestion on the ecological renovating, restoring, and planning were presented. The factors were selected according to our data resources and the factors weight is defined. The results indicate that using AHP model, the environmental evaluation can be performed in the loess gully-hilly region in northwest of China. In the study area, the quality, and degree and potential in use is not so good in the most of the study area. On the bases of quality evaluation, the environmental planning was developed.