A new method based on projection pursuit for natural grassland quality classific ation, called GQC RAGAPP for short, is presented in this paper. The basic idea of GQC RAGAPP model is to project high dimension indexes of natural grassland q uality classification to projective values in only one dimension space, to descr ibe classification structure by using a projective index function, to search the optimal projective directions according to the projective index function, and t o analyze the classification...