We designed, fabricated and evaluated a mono--tapered leaf spring made of carbon fiber reinforced plastics. To construct the leaf spring, a carbon/glass fiber hybrid lamination was selected. This selection was made in consideration of chipping resistance, impact resistance and fatigue-resistance.We constructed a prototype of the leaf spring which weighed approximately 2 kg including the front and rear steel eyes. In comparison with the steel spring, this represents a weight reduction of 76 percent.Prototypes were put through a series of evaluations both on the bench and on the vehicle. As a result, the leaf spring proved to be better than the steel spring in such practical performance areas as car handling, riding quality and endurance.