A mixture of fluoroalkyl iodide telomers represented by the formula: R_f(CF₂CF₂)_nI wherein R_f represents a fluoroalkyl group whose number of carbon atoms is in the range of 1 to 10, with the polymerization degree n equal to or more than k that is an integer of 3 or more, is obtained by reacting a fluoroalkyl iodide with tetrafluoroethylene in a first reactor followed by fractionating a first reaction mixture which contains fluoroalkyl iodide telomers of low polymerization degree, as well as by reacting the telomer with n of (k-1) separated from the first reaction mixture with tetrafluoroethylene in the second reactor.