Objective: A rapid method was established to judge the end point of blending process of Zhengtian pills by near-infrared spectroscopy, which was in order to improve blending efficiency of this preparation. Method: Near-infrared spectroscopy of blending samples were collected,then blending uniformity was calculated at different time. Principal component analysis( PCA) combined with Mahalanobis distance was used to identify the end point of blending process. HPLC was employed to determine the content of paeon...