ABSTRACT:- This study targets at finding the effects of methanol blending to gasoline on dynamic response of IC engine. The fuel blends were prepared by blending 0, 10 and 20 vol. % of methanol with a specified amount of gasoline. These fuel blends were designated as M0G100, M10G90 and M20G80, respectively. Base commercial gasoline (Octane No. is 81) was used in this study. The experiments were conducted on a single cylinder, four stroke variable compression “Varicomp” Dual Diesel /Petrol cycles with a dynamometric test unit type (GR0306/000/037A Prodit) under various engine speeds 1200 RPM up 2000 RPM for increment of 400 RPM at constant torque of (10 N.M), and compression ratio is 9 .The data acquired from these experiments present the relation between the cylinder pressure and the crank angle. For the purpose of investigating the vibration response of IC engine under dynamically loaded and ignition condition, the experimented cylinder pressure profiles of (Prodit) single cylinder four stroke engine for different percentage of methanol blending with gasoline base fuel, was assumed to be created in each cylinder of (Zetor-M-Type) in-line four cylinder-four stroke engine. Transfer matrix method (TMM) was adopted to calculate the vibration of the crankshaft for the latter engine. It is accounted for the shear effect and gyroscopic effect for the mathematical model of the crankshaft and the effect of unbalance forces, Also it's accounted for the dynamic loads that are applied on main and big end bearings , and two coefficients of damping and stiffness represented the oil film for each bearing. To embrace the theoretical side, a computer program (Fortran 90), which depends on the data acquired from the experimented work, is constructed to compute the vibration response along the crankshaft of engine for each fuel (M0G100, M10G90, M20G80) to compare the vibration for each case of cited mixture of fuel and to get the suitable fuel for engine. The result of this study showed that the M10G90 yields the best fuel for engine to get better vibration then M0G100 and M20G80.Keywords:- Internal combustion engine, crankshaft, vibration, gasoline, transfer matrix method