This art icle aims to const ruct an evaluat ion index system of agriculture and ecology security in the loess hilly region using the index selecting principle which combines reg ional features with scientific foundation, integrality with relat ive independence, feasibility w ith operat ion, and comparison w ith pert inence. In order to present the evaluation index system w hich conforms to this area, the conceptual model of the/Pressure) Condition ) Response (PSR) is used with the ecological problems in the loess hilly reg ion considered. The index system includes the three parts of system pressure, system condition and system response, which is composed of 10 first-grade indexes and 21 second-grade indexes.