Tolylene-2,4-diisocyanate(2,4-TDI)1 reacts with methanol through two simultaneous paths in the polyurethane reaction,which involve two different intermediates-tolylene-4-caxbamatic-2-isocyanate 2 and tolylene-2-carbamatic-4-isocyanate 3,and the final product is tolylene-2,4-dicarbamate 4.The-CH3 chemical shifts in benzene ring in compounds 1,2,3 and 4 can be easily tested and well distinguished,through which those four compounds are quantified and their kinetics are investigated.It shows that four rate constants for the tolylene-2,4-diisocyanate-methanol reaction in CCl4 at 50℃ are k1 =9.6×10-2h-2mol-2min-1k2=1.4×10-2h-2mol-2min-l,k3=4.0×10-3h-2mol-2min-1,k4=1.4×10-3h-2mol-2min-1.(k1 is the reaction rate constant from compounds 1 to 2; k2 is the reaction rate constant from compounds 1 to 3; k3 is the reaction rate constant from compounds 3 to 4; k4 is the reaction rate constant from compounds 2 to 4).