Sanchi,is an important herbal ingredient in traditional Chinese medicine with well documented clinic efficacy for strengthening weak heart.It is prepared by sundrying the fresh roots ofPanax notoginseng.Sundrying is a process involved with heating which can trigger Maillard reaction and change the chemical composition in the herb,but the influence of the process has been overlooked.To reveal the chemical changes due to the sundrying process and evaluate the subsequent influences on the chemical composition,changes in the contents of amino acid of P.