A high speed gated soft Xray multiframe image diagnostic system was developed for QiangGuangI generator, which was operated with a peak current of 1.5MA and a rise time of 80ns. In the system, a gated fourframe (3~5ns gate, 5~20ns separation) Xray camera, used in conjunction with a set of filtered pinholes was employed. Pinholes of 0.1mm and 0.3mm were used, which gave a spatial resolution of 0.56mm and 1mm, respectively. The pinholes were filtered with 2μm aluminized mylar. The system was sensitive to 150~300eV photons and to those greater than 550eV. Finally the last experimental results measured by this system in QiangGuangI generator were discussed.