Abstract: Five different shapes of fillet weld joint models are listed,using flank angle as the main controlling factor,The states of stress of these models are obtained by applying the elasto-plastic finite element method.The fatigue life of the surface cracks of the weld toe and the central part of the welding bead are calculated.A comparative study of the results obtained is made with those seen in relevant literature,and some conclusions useful to the designing of fillet weld joints of cylindrical oil storage tank,are derived.