Oxide dispersion strengthening (ODS) steels have been considered to be very promising for fuel clad materials for high burn-up operation of light water reactor and super critical water reactor. For improving the corrosion resistance, increasing chromium concentration, which often resulted in degradation of mechanical properties and thermal embrittlement, has been required. In this work, the effects of aluminum addition on the mechanical properties of high chromium ODS steels have been investigated. Various ODS steels which have 14 ∼ 22 wt% Cr concentrations were made by mechanical alloying method. In order to evaluate the mechanical properties and the effect of thermal aging, a miniaturized Charpy V notch test and tensile test were performed before and after aging. 1) The addition of Al resulted in the decrease in anisotropy of tensile properties, although it reduced the tensile stress. 2) The impact properties of 19Cr-ODS steel are improved by the addition of Al.