A small amount of various elements has been added singly to the duralumin (Cu 4%, Mg 0.5%, Mn 0.5%, rest Al) and the effect of elements on the change of dilatation on tempering and oh the corrosibility of duralumin has been examined. The results of the present experiment are as follows. (1) The small expansion and contraction below 100° and the change of dilatation in the vicinity of 300° were markedly retarded by the addition of Co (>0.49%), Cr (>0.64%) and Pb (>0.48%) (2) The addition of Bi, Cd, Co, Sb and Zn improves the corrosibility of duralumin. While the addition of Cr, Pb and Sn do not improve the said property, the addition of Ag, Fe and Ni causes deleterious effect.