Thekineticstudyofin-situcopolymerizationofanilinewitho-andp-methylanilinebyammoniumpersulfate(APS)hasbeencardedout.UV-visspectroscopicmethodwasusedtoinvestigatethecourseofcopolymerization.StructuralcharacterizationwasstudiedbyFT-IRspectralanalysis.Theelectronicspectraofthecopolymerspoly(aniline-co-p-toluidine)andpoly(aniline-co-o-toluidine)showblueshift.Theshifthasbeenobservedinthebandscorrespondingtoπ→π~*transitionaswellasintheexcitontransition.Theincreaseinabsorbancerecordedduringthereactionfordifferentconcentrationofaniline,o-andp-toluidineatvariousintervalsoftimeofpolymerizationreactionindicatesagrowthinthepolymerformation.Theresultingfirst-orderrateconstantwasusedtocalculatetherateofcopolymerformationusingtherateequation-d[A]/dt=kc~n.