The polymerization kinetics of 4，4'-biphenyldicarbonitrile I catalyzed by complex of 4，4’-biphenyldicarbonitfile with ZnCl2 was studied．The cyano group concentration was measured by infrared spectroscopic analysis using potassium ferricyanide as the internal reference．The results proved：the polymerization of 4，4'-biphenyldicarbonitrile is a second order reaction．The polymerization rate is directly proportional to concentrations of cyano group and complex．The rate Constants of polymerization are 0.808；1.058；1.249；1.632；1.808 1·mol-1.hr-．at 260°；270°；280°；290°；300℃ respectively．The activation energy of the polymerization is 12．4 kcal.mol-1．The polymerization rates of 4，4’-biphenyldicarbonitrile catalyzed by following eight co-mplexes of 4，4'-biphenyldicarbonitrile with chloride at 280℃ were measured The rate．constants are：I. TiCl4 1.42；I. 2ZnCl2 1.25；[FeCl3 0.785；I·2COCl2 0.706；I·SnCl4 0.418；I·AlCl3．0.396；I·2SbCl5 0.169；I·2BCl3 0.0247 1·mol-1·hr-1．The N1s binding energy shifts，measured by xvs(X-Rgy Photoelectron Spectroscopy)，are as follow：I·2ZnCl2 1.6；I·2CoCl2 1.5；I·SnCl4 1.3；I·TiCl4 1.2；[．FeCl3 1.1；I·2SbCl5 1.0；I·AlCl3 0.7；I·2BCl3 0.5 (e.v.) This fait shows tha the nitrogen atom in these complexes possesses less electron density than that in the 4，4'-biphenyldicarbonitrile molecule and then．it induces the carbon atom of the cyano group of these complexes to be more positive．This is favourable for the attack of the cyano group．by other 4，4’-biphenyldicarbonitrile molectfles therefore the rate of the polymerization is accelerated．The polymerization’mechanism may be.