Fluorine-containing block copolymers consisting of poly(2-hydroxyethyl vinyl ether) (poly-HOVE) and poly(2-(2,2,2-trifluoroethoxy)ethyl vinyl ether) (polyTFEOVE) with different degrees of polymerization were synthesized by sequential cationic polymerization of 2-(acetoxyethyl) vinyl ether (AcOVE) and TFEOVE, followed by hydrolysis of the acetyl protecting group. Poly(HOVE-b-TFEOVE) (m:n = 32:10, 28:13, 34:20, 34:31, where m and n represent the degree of polymerization of HOVE and TFEOVE segments, respectively) showed amphiphilic characters and was soluble in water and nonpolar solvents such as toluene. The surface tension of the polymer aqueous solution decreased to ca. 30 mN/m at polymer concentrations around 1 x 10(-4) mol/L. SAXS measurement of the aqueous polymer solution revealed that the polymers formed core-shelled spherical micelles at concentrations of 1.0 wt %. Poly(HOVE-b-TFEOVE) (m:n = 34:31) aqueous solution solubilized more hexafluorobenzene than the nonfluorinated amphiphilic block. polymer, poly(HOVE- b-n-butyl vinyl ether) did, which was confirmed by measurement of the UV absorption of each solution.