The Schiff base1-3 consisted of 4-methyl piperazine acetyl hydrazine and salicylaldehyde(L)and its Zn(Ⅱ)complex has been synthesized and characterized by elemental analysis,infrared spectroscopy,fluorescence spectra,1HNMR spectrum,thermogravimetric analysis and molar conductance analysis.Those characterizations speculated the possible components as follows: [Zn(L)2].The geometric configuration,vibration frequencies,atomic charge distribution,natural bond orbital(NBO)analysis,spectral analysis and the frontier molecular orbital of L were studied through the B3lyp method based on Density Functional Theory(DFT),which were performed by Gassian09 quantum chemistry package.Calculated results show that the lower calculated energy and zero-point energy of configurationⅡare easier to exist stably in terms of thermodynamics,and the lower gap energy of configurationⅡ(ΔE(HOMO-LUMO)= 4.32 eV)is the least relative in terms of kinetics.Based on the natural charges and electron configurations on the atoms of configurationⅡ,the nitrogen atom of the carbon-nitrogen double bond and the oxygen atom of salicylaldehyde may be likely to participate in the coordination.