INTRODUCTIONSince 2011, a three-dimensional (3D) scanning irradiation system has been utilized for treatment at the National Institute of Radiological Sciences-Heavy Ion Medical Accelerator in Chiba (NIRS-HIMAC). After the construction of fixed beam lines, we started design and construction of a superconducting rotating gantry. The construction of rotating gantry is completed in September 2015. Currently, beam commissioning for treatment is carried out. In this presentation, we will report the present status of the beam commissioning of our gantry.Scanning correction for BM field errorOur scanning magnets are located upstream of final bending magnets (BM7-10). Thus, it is necessary to correct the position dependent field error from BM7-10. Based on measured distortion ,we performed feedforward correction in current setting calculation of scanning magnets. As a result, scanned beam position are successfully corrected as same level with that in fixed beam line.DEPTH SCAN TECHNIQUETo suppress beam spread due to the multiple scattering and the nuclear reaction, we then developed a full energy scanning method. In this method, we prepare more than 200 energies ranging from 55.6-430 MeV/u, corresponding to the water-equivalent residual ranges of about 1-300 mm with 1 or 2 mm intervals behind the instruments for 3D scanning. To verify the beam delivery system for the full energy scanning, we performed several fundamental beam tests.