We are developing a compact X-ray nondestructive evaluation (NDE) system using 9.4 GHz X-band linac with 250kW magnetron. A conventional 1 MeV X-band machines use a large 1MW magnetron system. We have chosen the 250kW magnetron so that the RF heat loss is remarkably reduced. This design yields compactness and portable. This system consists of the X-band magnetron, modulator, thermionic 20kV electron gun, X-band linac and metal target of X-ray generation. We aim that X-ray spot size is less than 1mm. We designed the linac structure of the π mode at low energy parts and the π/2 mode at high energy parts by using updated commercial software. We finished to measure resonant frequency, and electromagnetic field on axis used by bead-pull method. These devices are to be applied to on-site NDE at petrochemical complex, nuclear- and thermal-power plants. We are also going to test the system at the Nuclear Professional School, the University of Tokyo this year. This paper presents the details of the system and experimental results.