A high-performance liquid chromatographic (HPLC) method coupled with chromatographic pattern matching was developed to differentiate whole chromatograms of raw and steamed Panax notoginseng objectively and quantitatively. The major peaks differentiating chromatograms of raw and steamed samples were also identified for the first time in this herb. The raw and steamed P. notoginseng roots and its products were successfully differentiated. The quantitative differences between the chromatograms were correlated to the duration of steaming. Chromatographic pattern matching allows rapid, simple, automated, and quantitative comparisons of complex chromatograms. It is a useful tool in ensuring safety and quality of herbal products.