[en] A series of Dy_1-xLu_xNi₂B_2C (x=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 LuNi₂B₂C-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=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=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(T)/(1-x) are approximately 90% of R ln4 and the effective magnetic moment normalized by Dy concentration is almost unchanged, which indicates that the magnetic ground state of Dy³⁺ does not show a pronounced change. (author)