In　this　paper,　GaN　nanoparticles　were　synthesized　from　the　complex　Ga(H2NCONH2)(6)Cl-3　in　the　flow　of　NH3　at　a　mild　temperature　(350　degrees　C).　Further　purification　was　performed　by　the　ethanol-thermal　method.　The　ethanol-thermal　method　also　prompted　the　GaN　nanoparticles　to　grow　into　an　anisotropic　morphology.　XRD　patterns　reveal　that　GaN　nanoparticles　have　crystallized　in　a　hexagonal　wurtzite　structure.　TEM　observation　shows　that　the　average　size　of　the　as-prepared　nanoparticles　is　about　5-10　nm.　The　photoluminescence　spectrum　exhibits　a　broad　green　emission　band　with　a　peak　at　510　nm.　It　can　be　known　from　the　first-principle　theoretic　simulation　by　the　TDDFT　method　that　this　fluorescence　emission　band　is　attributed　to　the　hydride　defects　of　VN-H　on　the　surface　of　GaN　nanoparticles.