Abstract: The guaiacol and vanillin lignin model compounds with aminated polyols were dissolved by butanone to prepare the solution with solid content 30%, and then mixed with MDI-50 as the molar ratio of —NCO to —OH is 1:1. The characterization of crosslinking reaction of these two aminated polyols with MDI-50 at ambient temperature was investigated by DEA, and the crosslinking reaction kinetics was investigated by FT-IR in this study. The kinetic equations of these two crosslinking reaction systems were obtained. The results indicated that the crosslinking reactions between these two aminated polyols and MDI-50 were similar in reactivity, and the reactions followed the n-order reaction kinetic model.