1 1 B NMR studies in Y(Ni 1 - x M x ) 2 B 2 C with M = Co, Cu, Pd and Pt were performed. The measured nuclear spin-lattice relaxation rates, T - 1 , 1 s, in the normal state suggest the density of states at E F for B site decrease by the substitution of these impurities for Ni site, which may be accompanied by the decrease of T c . In the superconducting state, on the other hand, T - 1 1 of 5 9 Co decreases with decreasing temperature exponentially as exp(-Δ/k B T c ) with no appreciable enhancement just below T c . The value of 2Δ/k B T c was estimated to be about 3 down to 0.5T c , which is close to the BCS-value of 3.5.