A series of Dy 1Àx Lu x Ni 2 B 2 C (x ¼ 0 {1) compounds have been investigated by X-ray diffraction and by examining the temperature dependences of electrical resistivity, magnetization and heat capacity. All the samples exhibit the same LuNi 2 B 2 C-type structure; and lattice parameters depend almost linearly on the Lu concentration x. The superconducting transition temperature T c decreases rapidly with increasing x, and superconductivity disappears at approximately x ¼ 0:2, then increases with a further increase in x. The magnetic transition temperature T M and the effective magnetic moment P eff decrease gradually with increasing x. The ferrimagnetic-like behavior emerges at about x ¼ 0:2; which can be the main reason causing the suppression of superconductivity. The temperature dependence of the magnetic entropy S m originated from Dy ions has been evaluated on the basis of heat capacity data. The saturated values of S m ðTÞ=ð1 À xÞ are approximately 90% of R ln 4 and the effective magnetic moment normalized by Dy concentration is almost unchanged, which indicates that the magnetic ground state of Dy 3þ does not show a pronounced change.