Based on the correlation analytic process and GM (1,1) model of the Grey System theories, the paper analyzes the influence of the technologic index of substance in the agricultural modernization upon the development of the agricultural economy in Hunan province. This result shows that agricultural chemical technology plays the most important role in the development of agricultural economy, and then electrization, irrigation and mechanization. The paper forecasts the development trend in the future of these factors by the GM (1,1) model, whi...