The aim of this study was to evaluate the feasibility of near infrared reflectance(NIR)spectroscopy in testing the protein content of chestnuts peeled and with peel.The Sample Set Partitioning based on joint X-Y distances method was performed to classify the calibration subset and the validation subset in order to improve the model performance.PLS regression models based on a population of 182 samples were established for chestnuts with and without peel respectively and the effects of different preprocessin...