Abstract: n order to analyze the influence on dynamics characteristics from delayed gamma-induced neutron for nuclear reactor of in-hospital neutron irradiator, which used to cure cancer with technology of boron neutron capture therapy (BNCT), the dynamics equation of point-reactor included the quantity, worth and decay constant of gamma-induced neutron was set by introducing neutron worth in reactor core and reflector in the one group diffusion equation. The calculation methods on generation rate of delayed gamma-induced neutron, the worth of neutrons generated from fission reaction or gamma-induced were also introduced. The total numerical calculation methods were studied with help of current calculation software and its sketch was shown. The mentioned parameters were calculated and analyzed for the nuclear reactor of in-hospital neutron irradiator. As a result, parameters of 9 groups delayed neutron were added to normal 6 groups. The tendency was analyzed and the good coincidence was verified with experiments from other research reactors which consist of beryllium in reactor complex.