Using a mechanical alloying-hot isostatic pressing method, new dispersion strengthened tungsten (DS-W) alloys containing TiO2 particles on grain boundaries have been developed for improvement of plasma facing materials for divertor components of fusion reactors. In this study, effects of the dispersion strengthening on the thermal change of microstructure and the thermal conductivity at high temperature were investigated. Within contrast to pure tungsten, the DS-W did not show significant microstructural change or a drastic decrease of the bending strength after annealing at high temperature.