A quick and nondestructive method for determining water content and viscosity of in-used PAG-based lubricants using near infrared technique was explored in this study.Partial least square(PLS)was utilized to establish the calibration models using first derivative spectra with wet chemistry as a reference method.Standard error cross validation(SECV)and correlation coefficient (R2)for each model are 0.95 cST and 0.929 for viscosity,and those for water content are 0.0234％ and 0.989,respectively.The results show that the presented method is fast,convenient and have a good reproducibility and accuracy for some lubricant property prediction.