The method of B3LYP/ 6-31G* in density functional theory (DFT) was used to optimize the geometrical configuration and study the vibrational frequency of GaNm(m=2-7) and Ga2Nm(m=3-6) neutral and ion clusters. The structures and stability magic number regularity of the clusters were obtained,all structures of these clusters are plane. The vibrational frequency of N-N band of nitrogen-rich GaN clusters is 2200 cm-1. There is N2 or N3 unit in the structures of all cluster,and the length of two N-N bonds of N3 of all clusters are equal mainly. The band gap range of nitrogen-rich GaN ion clusters is broader than nitrogen-rich GaN neutral clusters.