The prompt neutron spectra of 2 3 8 U fission induced by 10.17 and 12.12 MeV neutrons have been measured using a multi-segment fission chamber and two ST-451 liquid scintillator neutron detectors in conjunction with a double-TOF technique. Use of coincidence between the fission fragments and neutrons enabled the fission neutrons to be distinguished from other secondary ones. The detection efficiencies of the ST-451 liquid scintillators were determined by combining Monte Carlo calculation using a standard code NEFF4 with experimental calibration using a low-mass 2 5 2 Cf ionization chamber. The measured spectra can be roughly described by Maxwellian distributions. The Maxwellian temperatures are obtained by fitting equal 1.40±0.04 MeV for 10.17 MeV incident and 1.47±0.04 MeV for 12.12 MeV, respectively. The experimental spectra are compared with theoretical calculated ones by code FINESSE and the evaluation by ENDF/B-VI.