Relational database system for the fatigue strenght of crack initiation is implemented by using personal computer. This database system contains appending, updating, deleting and analysing functions, in order to process high cycle fatigue strength, low cycle fatigue strength and fracture toughness. Low cycle fatigue strength data is collected from the databook on fatigue of metals published by JSME. Methods of fatigue life prediction for ferrous metals and aluminium alloy are reviewed through database implemented. For ferrous metals under axial loading, Manson's Universal Slope method seems more reasonable than Mitchell's method. And, for aluminium alloy under axial loading, modified Manson's Universal Slope method, which is modified by using the relation between fatigue strength exponenet and ratio of fatigue stregth coefficient to tensile strength, is used to predict fatigue life.