We study influence of a galactic central supermassive black hole (SMBH) binary on gas dynamics and star formation activity in the galactic central region by making three-dimensional Tree+SPH simulations. Due to orbital motion of SMBHs, there are various resonances between gas motion and SMBH binary motion. We have shown that these resonances trigger gas concentrations and filaments in the galactic central region and the formation of small gaseous spiral arms around the SMBH binary. In these regions, star formation becomes very active. As the result, a nuclear star burst occurs in the galaxy.