Existence of non-lint materials (or botanic trash) within commercial cotton bales degrades their market value, requires a further cleaning process, and compromises finished product quality. To meet the challenge of assessing the trash content, a number of approaches have been in practice. In the US, one term to assess the degree of trash amount is leaf grade, which was originally determined by qualified US Department of Agriculture's AMS cotton classers via a visual inspection procedure. Recently, the AMS has revised the protocol for cotton leaf grade classification, by replacing the classer's leaf determination with instrumental leaf measurement from cotton classification HVI TM system. In this study, visible/NIR spectra were acquired to explore the potential for the discrimination of cotton samples with various leaf grade categories. Seven-class classification models in different spectral regions were developed to optimize the identification efficiency. Results indicated that using the model in the 1105-1700 nm NIR region could reach an acceptable separation of $95.0%, with a 89.9% correct identification in validation set and a 100% success in calibration set. Furthermore, factors of influencing the correct classification were discussed briefly.