An attempt was made to determine v, the mean number of neutrons produced per fission of U-238 induced by 14-Mev neutrons. The neutrons were supplied by the Tsing Hua 3-Mev Van de Graaff accelerator using the reaction T (d, n) He'. The fissile material was used in the form of Us O8.An experimental determination was made of the ratio of the number of neutrons detected in a given time with the fissile material in place surrounding the source and with the fissile material removed. A manganese bath containing manganese sulfate was used as a neutron detector for this purpose.The value, 4.36±0.34 neutrons per fission was obtained and is in good agreement with values obtained by others.