PURPOSE: To improve fire-extinguishing properties and increase stability during storage by preparing a fire-extinguishing agent composition with the formulation of a fluorine surfactant containing ether oxygen atoms and the hydroxyl group as shown by a specific formula.

CONSTITUTION: A surfactant is prepared based on the formula I: wherein Rf represents the polyfluoroalkyl group with a carbon number of 3W20, X the bivalent coupled group containing ether oxygen atoms, and R the alkylene group, Y represents the formula II or III: wherein Z represents the alkyl group containing the anionic group, R1 H, the alkyl group and hydroxyalkyl group, R2 H, the alkyl group, the hydroxyalkyl group, and one alkylene group in cooperation with R1; R3 represents H, the alkyl group and the hydroxyalkyl group. A fire-extinguishing agent composition is prepared by formulating the surfactant shown by the formula I.