Oxygen-transferable perfluorocarbon compounds having 9 to 11 carbon atoms such as perfluorodecalin, perfluoro(C.sub.3-5 -alkylcyclohexanes), perfluoro(C.sub.4-6 -alkyl tetrahydropyrans), perfluoro(C.sub.5-7 -alkyltetrahydrofurans), perfluoro(C.sub.5-7 -alkylmorpholins) and perfluoro(C.sub.9-11 -trialkylamines) are emulsified in a physiologically acceptable aqueons solution such as Ringer's solution by the aid of a phospholipid as emulsifier and a fatty acid of 8 to 22 carbon atoms, alkali metal salt or monoglyceride thereof as emulsifying adjuvant. The emulsion is stable for a considerable period of time and contains particles having a particle size ranging from 0.05 to 0.3 .mu.. It is usable as a blood substitute or a perfusate for preservation of the internal organs.