Extraction process trajectory of Danhong injection by near-infrared (NIR) spectroscopy in conjunction with multivariate data analysis techniques was developed for in-line monitoring of extraction process. To capture the variation of batch process, the use of score, Hotelling T2 and DModX control charts was investigated for real-time monitoring of extraction process. Various abnormal behaviors of the test batches were detected in time by comparing the extraction process trajectory. It was concluded that the process trajectory for in-line quality control based on NIR spectroscopy was a feasible technology tool of the total process quality control during traditional Chinese medicine (TCM) manufacturing process.