The electronic structures of anti-perovskite-type intermetallic compound Ni3AlXy (X = B, C, H; 0 < y < 1) have been calculated using coherent-potential approximation (CPA) within the local-density approximation (LDA). Ferromagnetic moment in Ni3Al rapidly decreases with increasing y for every dopant X, even though the lattice is more expanded than non-doped Ni3Al.