In this study， soluble solids content （SSC）， total acid （TA）， sugar-acid ratio and firmness of postharvest peach fruits were determined by near infrared spectroscopy. The effects of different spectral pretreatment methods on the models were discussed. Partial least squares （PLS） models of the physical-chemical properties of peach fruit were established and predicted. Before modeling， variance analysis and Pearson correlation analysis were used to study the relationship between several indexes and storage time. For SSC， TA， sugar-acid ratio and firmness， the correlation coefficient of calibration set （Rc） of SSC， TA， sugar-acid ratio and firmness optimal PLS model were 0.93， 0.69， 0.74 and 0.97， respectively， and correlation coefficients of the validation set （Rp） were 0.79， 0.69， 0.68 and 0.95， respectively. The root mean square error of cross validation （RMSECV） were 0.56， 0.11， 4.24 and 8.81， respectively. The root mean square error of prediction （RMSEP） were 0.89， 0.10， 6.02 and 16.22， respectively. The results showed that near infrared spectroscopy was feasible for the rapid detection of SSC and firmness of peach fruit， while the quantitative models of TA and sugar-acid ratio needed to be further optimized. This study provides a technical reference for the non-destructive determining and quality control of juicy peach during low-temperature storage in practical production.