Water holding capacity (WHC) is an important quality characteristic of fresh pork. It is necessary to determinate it by a rapid and nondestructive method in order to reduce the loss of meat. Near infrared spectroscopy as a new method was proposed for rapid and nondestructive measurement of WHC of vacuum-packed pork loin. Two reference methods for measuring water holding capacity were used to evaluate the water holding capacity, i. e. drip loss and press method. The acquired raw spectra were pretreated by Savisky-Golay smoothing and second derivative, respectively. A total of 106 samples were used in the experiment. The samples were divided into calibration set and validation set. The calibration set was used to set up calibration model and then the model was adopted to predict the samples of validation set. The partial least square regression (PLSR) was used to build calibration model. The results show that the correlation coefficient for drip loss and press method is 0.74-0.79. It shows that evaluating the water holding capacity of vacuum-packed fresh pork loin using near infrared spectroscopy in diffuse reflection mode is better than those results with reflectance or transmission.