Sandarac resin, a natural gum base, is described as "a substance composed mainly of sandaracopimaric acid obtained from the secretion of sandarac trees" in the List of Existing Food Additives in Japan. To evaluate its quality as a food additive, the main constituents in a sandarac resin product were investigated. Three constituents were isolated and identified as sandaracopimaric acid, sandaracopimarinol and 4-epidehydroabietic acid by MS and 2D-NMR. Quantification of the main constituent, sandaracopimaric acid, was performed by HPLC and its content in the product was determined to be 11.6%.