Fluoropolymers F,2311, and F,2314, samples were irradiated by neutrons of 1.23 MeV in average energy up to fluences of 1.5×10,13, / cm,2, and 2.5×10,13, / cm,2, and their static and dynamic mechanical properties and molecular weight were determined. It indicated that static mechanical properties of the F,2311, samples and tensile intensity of the F,2314, samples increased with the neutron fluence, whereas compression intensity of the F,2314, samples decreased with the neutron fluence. Molecular weight of both the fluoropolymers increased with the neutron fluence. Little changes were found with dynamical properties of the F,2311, samples, whereas dynamical properties of the F,2314, samples decreased with the neutron fluence.