[en] In this paper, the burn-up characteristics of a 200 MW_e molten-salt reactor are studied. This reactor has a three-region core in order to reduce the peak in fast neutron flux distribution. The reactor is operated for 30 years with the load factor of 0.75. The fuel is fed to the reactor every 33 days. The chemical processing of the fuel salt is performed every 7.5 years. Based on calculations using the nuclear analysis code SRAC2006 and the burn-up analysis code ORIGEN2, the following results have been obtained. (1) The graphite moderators can be used throughout the reactor lifetime without replacement. (2) The reactor is self-sustainable having an average fuel conversion ratio of 1.01. (3) The initial inventory of ²³³U is 1.13 t, net feed in 30 years is 0.34t; thus, the necessary amount of ²³³U is 1.48 t. (4) Pu isotopes are produced at 1.5 kg and minor actinides at 27 kg per 1 GWe output in 30 years, which are absolutely small compared with those produced by BWR. (author)