In the previous paper, a new method for estimation of fatigue strength under random loading condition was proposed, and the method is combined fatigue tests with calculations. This method was confirmed experimentally and shown to be useful in estimating fatigue strength of structures for random loading. In this paper, using the proposed method, fatigue strength diagrams for butt and fillet welds of mild steel are obtained for random loading with an exponential distribution. In addition strength diagrams for these joints are calculated using DOE guidance and AWS-Code. Fatigue strength diagrams proposed by authors are compared with those by guidance and code. As a result, the safety factor considered in guidance and code is larger than the one in other types of fracture, such as buckling and yield.