In this research work, we studied theoretically the structural properties of (5H-tetrazol-1-yl)(triphenylphosphine)gold or [Au(tetz)(PPh3)] by density functional theory (DFT) method at LANL2DZ level. All calculations were performed at 298.15 K and 1 atmosphere. Firstly, the bond lengths, bond angles, dihedral angles and natural charge density on atoms of the compound were calculated. The dependence between the experimental and calculated indicates a great convergence. The results have provided that the molecular structure of the compound is linear environment around gold atom. According to the calculations, the total natural charge of gold atom is consistent with the total number of electrons in the isolated gold atom. Natural bond orbitals (NBOs) analysis was then calculated at studied level of B3LYP (Becke, 3 parameter, Lee-Yang-Parr) theory. The NBO analysis revealed that the largest negative and positive charges are located on nitrogen (that coordinating to the gold) and phosphorus atoms, respectively.And also, it showed that the phosphorus atom uses more p orbital for formation of σ(Au-P) bond to formation of σ(P-C) bond.