Abstract: Based on Aldrich’s method of separating rosin adducts from rosin mixtures, a methcd of separating rcsin-maleic anhydride adducts from maleic mcdified rosin and determining the content of the adducts has been devised. Optimun conditions for separation have been investigated. Separative adducts can be first extracted by methanol-heptane-water or methanol-petroleum ether (60o-90℃)-water system and then determined by titrimetry or gravimetry with an experimental error of ±2-6%.?75