Intermetallic compound MoSi2 is expected to be one of the light heat-resisting materials. However, MoSi2 suffers from accelerated oxidation at low temperatures called as 'pest oxidation'. In this study MoSi2 was boronized to improve its low temperature oxidation by molten salt process. Molybdenum boride was formed on the surface of MoSi, and no pest disintegration was observed after cyclic oxidation test. (C) 2003 Elsevier Science B.V. All rights reserved.