An investigation on the as-cast fatigue property of horizontal continuous casting (HCC) ductile iron bar, under transversal loading condition, were conducted. The results showed that the fatigue limit value of tested samples can reach 260 270 MPa, and the comparison test sample of sand cast ductile iron only get 180 MPa under the same experiment conditions. The fine and round shaped graphite nodules and compactive structure and the very little amount of non-metallic inclusions in the matrix are the main factors which contribute to the high fatigue property.