<p>The structures of transition metal-doped silver clusters M@Ag₁₂ (M = 3d-5d) have been obtained by genetic algorithm and density functional theory method. The computational results reveal that the global minimum structures of M@Ag₁₂ clusters include six types: perfect icosahedron cage (I_h) with 20 congruent triangular faces (Cr, Mo, W, Re); icosahedron cages clusters in C_s, C_{2 h} and D_{2 h} symmetry (V, Nb, Ta, Hf); half cage structures in C_s symmetry (Sc, Ti, Y, Zr, La); half cage structures in C_s symmetry with one Ag atom extending outside the structure (Mn, Fe, Co, Tc, Ru, Rh, O_s); double layered structures with C_s symmetry (Ni, Cu, Pd, Pt); oblate structures in C_2v symmetry (Zn, Hg); structures in C₁ and C₂ symmetry (Ag, Cd, Au). Average bond lengths of M-Ag, Ag–Ag and binding energies of M@Ag₁₂ clusters are obtained. According to the stability analysis, Cr@Ag₁₂, Mo@Ag₁₂ and W@Ag₁₂ are magic number clusters because their valence electrons follow 18e-rule. Moreover, the HOMO–LUMO gaps and binding energies of them are big. The superatomic electron orbitals of Cr@Ag₁₂, Mo@Ag₁₂ and W@Ag₁₂ are all |1S²|1P⁶|1D¹⁰|. The partial density of states, infrared spectroscopy and Raman spectroscopy of Cr@Ag₁₂, Mo@Ag₁₂ and W@Ag₁₂ clusters have been calculated and discussed.</p>