Abstract: The paper used near infrared spectroscopy (Grating, InGaAs detector), with translation, smoothing, derivative and partial least-squares regression, then a determination mode of nitric acid in water was established. The prediction results compare with the international standard method, the correlation coefficient R is 0.999 7, and the minimum detectability is 0.03 mol/L, measurement range is 0.10-3.00 mol/L, RSD＜5%. The method is simple and rapid, it does not need much chemical reagents, and it can also be suitable for fast determination in worksite.