Cold rolled and high strength steel were used for vehicle bodys to satisfy environmental regulation and improve fuel ratio. This paper presented a method far determining the fatigue life of cold rolled steel sheet EZNCEN and high strength steel sheet HS40R spot weldment used in vehicles. We can estimate the fatigue life of the spot weldments from the MSC/FATIGUE using the finite element method. The maximum load is found in the nugget part of both surfaces. The cold rolled steel and the high strength steel showed the maximum stress 746MPa and 730MPa in the effective nugget part when the weld current was 8KA and 7KA, respectively. Also the some weld current of the cold rolled steel and high strength steel is applied, the fatigue life of high strength steel is obtained about four times longer than the cold rolled steel.