The value of the volatile basic nitrogen of meat is an important index to determine the freshness of meat. It is difficult to meet the demand of fast and non-destructive measurement by means of classical semimicro-quantitative nitrogent method. A model to predict the value of the volatile basic nitrogen based on near-infrared reflectance spectroscopy was established. Cluster analysis methods were applied to deal with the data of NIRS. If the content of TVB-N is more than 11. 6 mg x (100 g)(-1), the back pork may be rotten. The result shows that using NIRS could indicate the freshness of meat quickly and non-invasively.