Triphenylphosphine (TPP) was used as the catalyst for reversible chain-transfer catalyzed polymerizations (RTCPs) of styrene and methyl methacrylate for the first time. The polymerizations showed the typical features of “living”/controlled radical polymerization, and well-defined polymers with designable molecular weights and narrow molecular weight distributions (Mw/Mn < 1.35) were obtained. In addition, RTCP of styrene using TPP as a novel catalyst not only could be conducted in the presence of a limited amount of air but also did not destroy the controllability over polymerizations.