Since Phosphor bronze (Cn-Sn-P alloy) has intensity and high thermal conductivity, it is used for the valve guide of high rotation and high output engine. Moreover, since its rubbing characteristic is higher than general material, clearance with valve can be made smaller and attachment of the circumference of valve and operation accuracy can be improved. This brings about the greatest effects thus the stress fall of valve system, valve stick prevention, and valve guide crack prevention.