Abstract: Slope position is an important factor describing relief in the hillslopes. The automatic extraction of slope position has great significance in the natural habitat analysis and geo-ecological process modelling. Based on digital terrain analysis, we propose a slope position classification method which considers both slope profile and relative position index. And then the algorithm of the method was designed and programmed. According to forest resources survey rule, the slope position extraction test was carried out in the western mountainous areas of Beijing based on DEM data at the 1∶250 000 scale. The test has achieved the expected result. The result showed that the method can realize the localization of relative position index calculation and slope profile segmentation,and make the classification more objective and reasonable.