Abstract: 【Objective】 Based on the NIR network that constructed in main grain producing areas in China, the quality distribution monitoring of wheat, the variety discrimination, and producing area classification were studied.【Method】The Infratec 1241 NIR analyzer from FOSS Company was used to construct the grain NIR network. This network consisted of the main instrument, reference library, network administration center and several satellite instruments that distributed in the main grain producing areas of China. Combined with GPS and GIS technology, the network was used to analyze the quality distribution of winter wheat in 2009. The collected NIR spectra were analyzed by Soft Independent Modeling of Class Analogy (SIMCA) , and the classification models for variety, and producing provinces of wheat were constructed. 【Result】The results showed that it could save cost and keep unitive accuracy and precise by using network center to construct and manage the calibration models. All the satellite instruments had good constancy with the main instrument, and their correlation coefficients were over 0.92. Based on the NIR network, the wheat quality distribution map in different scales could be obtained, thus obtained the quality distribution information of wheat. With the spectra collected from NIR network, the wheat variety and producing area could be discriminated. The classification accuracy for five varieties of wheat in Shandong province was over 80%, and for discriminating wheat that produced in Beijing, Shandong and Jiangsu, the classification accuracy was over 90%. 【Conclusion】 The results showed that NIR network had a potential in analyzing the quality distribution, variety and producing areas discrimination for wheat. It could provide large scale data support and thus be used to guide the wheat purchase, quality management and decision-making.

Key words: near infrared network , near infrared spectroscopy , wheat , grain