Abstarct: The engine mounting bracket is connected to the engine on one side and to the vehicle body on the other side. Engine mounting bracket should be designed to absorb vibrations that generated from the body to the motor and vice versa. In addition, engine mounting bracket should withstand weight of the engine, the dynamic and vibrational loads caused by movement of the vehicle on the road. Therefore, engine mounting brackets are generally designed to have a sufficient fatigue life within a defined range of cyclic forces. Although in large range of load caused by accident, this part should be break to minimize the side effect. This thesis investigated the high cycle fatigue life of an aluminum engine mounting bracket. Firstly, a finite element model was set up to evaluate this part especially in critical point under static loads. Results show that under the tensile force of 3000 N, FE model can predict experimental deflection of engine mounting bracket with 4% error. In addition, the variation of compressive experimental results in 5000 N with FE model is less than 2%. Secondly, the fatigue life of the part was estimated under cyclic loads using numerical methods. Result show that the original engine mounting bracket did not have enough strength under fatigue loads. So, root cause analysis was done on failed parts using combination of numerical methods and experimental inspection. Numerical analysis of fatigue life prediction had good agreement with experimental results and predicted the critical points and part sensitivity correctly. Experimental inspection of original and improved parts showed that increase of fillet radius, local increase in the thickness of the part in the critical area had significant effect on fatigue life of engine mounting bracket. Also, removal method of casting burs in separation area of casting mold was modified that can increase of fatigue life in engine mounting bracket. Finally, the fatigue crack propagation was investigated using experimental methods monitoring of part stiffness under fatigue test.