Abstract: NIR spectra were collected under the condition of continuous altering the water content in to-bacco leave samples.The total sugar,nitrogen and nicotine were determined by using corresponding NIR quali-tative predictive methods.Results showed that the absorbance of NIR was obviously increased with the in-crease of water content in tobacco samples,which affected the prediction of chemical compositions.The predic-tive errors decreased with the increasing of water content in sample when the water content was higher than 10%.The predictive errors of total sugar,nitrogen an nicotine caused by the differences in sample water con-tents could be neglected when the water content was less than 10%.