The absorption spectra of photoinitiator cyclopentadiene-Fe-naphthalene tetrafluoroborate salt ([Cp-Fe-Naph]BF4) and ferocinium tetrafluoroborate salt([Cp-Fe-Cp]BF4), in two solvents have been studied. The influence of irradiation on the solution of photoinitiator has been observed. The kinetics of photolysis has been determined by real-time UV absorption spectrum. The results show that the photolysis reactions of two initiators are the first order reaction, the rate constant of photolysis reaction are 0.72 and 0.65 min-1, respectively. The photoinitiated mechanism of [Cp-Fe-Cp]BF4 was obtained.