Radical polymerization of methyl methacrylate (MMA) initiated by various diacyl peroxide-amine systems wore studied．Benzoyl peroxide (BPO) and lauroyl peroxide (LPO) were used as diacyl peroxide component，N，N-dimethyl aniline (DMA) and its para substituted derivatives，i.e.，N，N-dime thyl-p-toluidine (DMT)，P-hydroxymethyl-N，N-dimethyl aniline (HDMA)，p-nitro-N，N-dimethyl aniline (NDMA) and p-dime-thylamino benzaldehyde (DMAB) were used as amine component．It was found that the diacyl peroxide．DMT aystems always give higher rates of bulk polymerization Rp of MMA than the organic hydroperoxide．DMT systems with the following descending order：BPO-DMT>LPO-DMT>CHP (cumene hydroperoxide)．DMT>TBH (tertbutyl hydroperoxide)-DMT．The aromatic tertiary amines posses obvious structural effect on the Rp values in the diaeyl peroxide-amine system．Thus．the para．substituted electron-do-aating groups on the ring of the，aromatic amine molecule increase Rp while the elee-tron-withdrawing groups decreased it with the following descending order as DMT> HDMA>DMA>NDMA≈DMAB．The overall aetiration energies E of MMA polyme．rization were determined．the kineffcs of polymerization of MMA initiated with BPO-DMT system were studied and its rate equation was determined as Rp=K『BPO]0.5[DMT]0.5[MMA].