Recent high power klystron status in KEK

In KEK there are three big projects such as KEKB project, Japanese Hadron Facility (JHF) and Linear Collider project (JLC). All projects include the linear accelerator, high power klystrons are key issues to develop them. In KEKB project, 59 S-band high power pulse klystrons are used and now under the commissioning. These S-band tubes were developed from the previous 30-MW klystron and produced 50-60 MW. JHF is the future plan of KEK and had a 200-Mev proton linear accelerator. We are now developing a UHF klystron (frequency of 324 MHz, peak power of 3 MW and rf pulse duration pf 650 microseconds). In JLC we have been developing the X-band high power klystrons under the collaboration between KEK and BINP. Recently 2D and 3D MAGIC code enable us to design klystrons more realistically. This report describes those three kinds of klystron developments.