Korea Accelerator and Plasma Research Association (KAPRA) is undertaking the first phase R&D for the 1 MW, CW 700 MHz klystron, which is targeting the future stage of the Proton Engineering Frontier Project (PEFP) accelerator at Korea Atomic Energy Research Institute (KAERI). The objectives of the first phase R&D are: (1) setting up all infra structures/procedures for the design and fabrication, (2) developing a prototype klystron for proofs of principles, and (3) making a performance test of the prototype at a reduced duty. The second phase R&D is supposed to cover full power, CW operation and reliability issues. A triode type electron gun, cavities, an output RF circuit, an RF window, a beam collector and an electro-magnet were designed to produce desired output rf power. Some parts were fabricated and tested, which is also briefly introduced in this paper. (c) 2005 Elsevier B.V. All rights reserved.