There were many evaluation methods of corrosion fatigue endurance properties of suspension springs, depending on spring manufacturers, as many factors affect the properties. Therefore, it has been desired to standardize the evaluation methods. This committee performed theoretical studies as well as experiments on corrosion fatigue. A new evaluation method is recommended on the basis of the experimental results that crack length evaluated from residual fatigue life is a good parameter to compare corrosion fatigue performances of suspension springs relatively.