The polymerization of styrene (St) initiated by 1,4-dimethyl-1,4-bis(p-anisyl)-2-tetrazene (1a) was studied kinetically in benzene. The polymerization proceeds through a radical mechanism. The rate of polymerization is proportional to [1a]0.5and [St]1.0. The overall activation energy for the polymerization is found to be 81.2 kJ/mol within the temperature range of 65 to 80°C. The activation parameters for the decomposition of1aat 70°C are kd= 1.88 × 10−5s−1, δH‡ = 133.1 kJ/mol, and δS‡ = 29.9 J/mol·deg.