[en] Neutronic Analysis of JRR-4 has been performed under the reduced enrichment program of the research reactors. The fuel selected is low enriched uranium silicon dispersion type (silicide fuel) and its uranium density is 3.8g/cm³. Almost of calculations were done using the SRAC code system developed by JAERI. The results obtained by the calculations are as follows. The reactor core has enough excess reactivity within the range to control and operate the reactor safely. Moderator void, moderator temperature and fuel temperature reactivity coefficients are always negative. Neutron fluxes in irradiation pipes are almost same level as the present core. As a result, the use of the silicide fuel of 3.8g/cm³ uranium density has been shown to be satisfactory for the core performance required in JRR-4, and has been adopted with the final decision. (author)