Abstract: As there are many different kinds of medicine on the market, it's significant to regulate medical market and to ensure people's medication safety by identification analysis of different brands of drug. In this study, spectral library discriminant analysis was applied to establish the qualitative identification model for different brands of left cetirizine hydrochloride tablets based on Near-Infrared Diffusion Spectroscopy. The spectral pretreatment method which was used consisted of vector normalization method and derivative method. Then the validation set was used to test the model. The results showed that the model couldn't correctly identify two samples of the same manufacturer,but samples from different manufacturers were classified correctly by the discriminant model, and the accuracy was 100%. This method can be used for rapid identification of similar medicines from different manufactures.

Key words: Fourier optics, near infrared spectroscopy, Levocetirizine Hydrochloride Tablets, discriminant analysis, rapid identification