Novel sterically hindered chain extender, 2-acetyl-ethylenediamine (MEDA) was synthesized by acetylating of ethylenediamine(EDA) with glacial acetic acid in presence of phosphoric acid, in order to reduce high reactivity of synthesizing polyurea and study its kinetics equation. Its chemical structure was confirmed through FTIR and 1H-NMR analysis. Polyureas were synthesized by reaction of 4,4’-dipheSuperscript textnylmethane diisocyanate(MDI), amine terminated polyether(D-2000) with different chain extenders. The reaction kinetics of polyurea curing process was studied by FTIR. The results showed that extending reaction with MEDA was second order kinetic mechanism, its apparent activation energy was 36.81 kJ•mol-1.