Twoiron-arenecomplexphotoinitiatorswithdifferentsubstituentsinareneligandsweresynthesized,theiractivitiesininitiatingphotopolymerizationofcyclohexeneoxide(CHO)werecomparedwiththatofIRGACURE261,acommercializedphotoinitiatorfromCiba-Geigy.Ahigheractivitywasfoundwhentheareneligandwassubstitutedwithastrongerelectrondonatinggroup.ForthesysteminitiatedbyIRGACURE261theconcentrationofactivecentersinCHOpolymerizationwasdeterminedanditwasfoundthattheconcentrationismaximumataround35℃.Thepost(dark)polymerizationwassignificant,thepolymerizationyielddecreasedwiththeincreaseofirradiationtemperatureandincreasedwiththeincreaseofpostpolymerizationtemperature.TheresultsareinterpretedbasedonthemechanismproposedbyLohse,etal..