Abstarct: Recently, spintronic has considered widely in electronics industry, condensed matter physics and materials chemistry. Searching for suitable spintronic is a main but crucial task. Some of the importance of Electron spin devices compare to electron charge is one degree of freedom more than similar electronic system, long lasting coherence and spin relaxation time. in this research We are looking for finding structures of Gallium nitride (GaN) semiconductor with specific properties in transport studies. On the other hand we investigate the electronic and magnetic properties of pure Gallium Nitride nanoribbon and doped by transition mextal impurities (Cu, Fe, Mn, and Cr) and Defects in this nanoribbon with spin polarized density function approach and generalized gradient approximation using SIESTA computation code. Then, calculate transport properties of pure and Defects in GaN nanoribbon with the non-equilibrium greens function (NEGF) and generalized gradient approximation using TRANSIESTA computation code. The results of magnetic and electrical studies revealed that presence of dangling bonds inside of the Gallium nitride structure and their location and edge of the structure, lead to half mextallic properties, magnetic mextal and magnetic semiconductors. The investigation of transport properties indicates that the most current occurred for down spin to both zigzag and armchair nanostructure, especially in zigzag nanostructure and in detail for device type one in 0.75 voltage and 27 microampere and the best filtering is related to devices type 5 and 6 for 100% filtering in 0.25 voltage. In devices type 1, 4, 5 and 6, negative differential resistance (NDR) phenomena has been occurred and the best negative differential resistance (NDR) behavior was obtained in the devices type 1 and 6. baxsed on the results, it is possible to gain a 100% spin polarized microampere current from a pure nanoribbon Gallium nitride structure without using magnetic doping or applying gate voltage.