Abstract: Objective:The technique for determination acidity of pomegranate juice was studied by using nearinfrared spectroscopy. Methods:Pomegranate juices from different origins were served as thesample.Preprocessing method of near infrared spectroscopy data was determined and the feature were extracted by principal components analysis. The three parameters of support vector machine (SVM) were optimized by genetic algorithms ( GA) . The model for determination of acidity in pomegranate juice by near infrared spectroscopy was established. Results:The root mean squared error (RMSE) and the determination coefficients of the models for validation were 0.01359 and 0.9928 respectively. The model had a good prediction performance.Conclusion:Near-infrared spectroscopy technology could be used for the quantitative detection of pomegranate juice acidity.