Macroinitiator （PAN-Br） and block copolymer (PAN-b-PZDMA) are synthesized using Atom Transfer Radical Polymerization (ATRP). The viscosity-average molecular weights of PAN-b-PZDMA we prepared are 7507，8517，9905 respectively. The molecular structures of macroinitiator and block copolymer (PAN-b-PZDMA) are characterized by 1H-NMR and FT-IR. It was shown by TGA and DSC that the thermal stability of block copolymer is promoted by the block of PZDMA in copolymer.