The theoretically calculated modes and optimized structure parameters of 3-amino-1,2,4-triazole have been computed with Density Functional Theory 9for two important methods) by using 6-311++ G9d,p) basis level. We have calculated all data by using Gaussian 09W. The theoretical structure values and vibrational frequencies of investigated compound have been found to be consistent with the experimental values. It was concluded that the optimized molecular geometric parameters 9bond lengths and bond angles) and theoretical frequencies are slightly deviated from the experimental values. Because, in theoretical calculations we have assumed that isolated molecule is in gas phase. But in experiments in fact, molecule is solid phase. So, inter-and intra-molecular interactions have been isolated from real situation. In summary, this study will provide support in future spectroscopic and other related studies.