Abstract:Dry dondey skin. defatted in advance with hair scraped off, was separately solubilized by heating in sealed tubes at 130 ℃ for 2, 4 , 6. 8h. .The resultants were clarified and dried as Ejiao, whose yield appeared to reach maximum after4h heating. Absorptivities of all four kjiao prepaiations were in good approximation to standard gelatin. However,their intrinsic viscosity declined in ordei of prolonged solubilization process, indicating that depolymerization of donkeyskin gelatin F.ad takezi place. In addition significant degradarion of dermatan sulfate, another constituent of Ejiao,was detected electophorenically and photometrically .