Poly(5-vinyltetrazole)(PVT) was synthesized through the tetrazole-cyclization reaction of polyacrylonitrile with sodium azide and ammonium chloride. The structures of PVT were identified by NMR,IR,elemental analysis. Moreover,some properties of PVT were studied by X-ray diffraction(XRD),DSC-TG and sensitivity testing. The results show that PVT has two exothermic peaks: the first one (T_d=239，274 ℃) is attributed to decomposition of the pendanted tetrazole group and the second (T_d=369.9 ℃) is attributed to thermal decomposition of the polymeric residue. The acid value of PVT (containing water) was determined to be 8.50 mmol·g^-1 by neutralized titration with 1.0 mol·L^-1 NaOH,and the tetrazole content of PVT calculated via acid value can reach up to 96.62mol%.