Oxidation behavior of Al-rich Mo(Si,Al)(2) base alloys, which is a candidate material for the oxidation resistance coating on Nb base structural composites, Were investigated by thermogravimetry. The Mo(Si,Al)(2) base alloys containing Mo-5(Si,Al)(3) up to about 10 vol% exhibits excellent oxidation resistance at temperatures ranging from 780 to 1580 K, particularly at 1580 K due to continuous Al2O3 layer development. To evaluate the applicability of the Mo(Si,Al)(2) base coating, plasma spraying on Nb base composites were undertaken. However, interface reaction layer was found to form during the following heat treatment. Preparation of Mo(Si,Al)(2)/Al2O3/Nb layered structures via powder metallurgical process was attempted to preclude diffusion reaction between coating and substrate.