The geometries,stabilities,electronic,and magnetic properties of Mn4TM(TM=3d,4d)clusters have been investigated systematically with the generalized gradient approximation density functional theory.Except Mn4Tc,the most stable structures for Mn4TM clusters are all the distorted triangular bi-pyramid structure with the transition-metal atom at the vertex or at the middle plane.All doped clusters show unexpected large average binding energies compared with pure Mn5 cluster,indicating doping could stabilize the host cluster.The systemic study of average binding energies and HOMO-LUMO energy gap demonstrate that the Mn4V,Mn4Ni and Mn4Zr are actually the most stable cluster.For entire Mn4TM clusters,the total magnetic moments are variously increased than that of pure Mn5 cluster,except the Mn4Tc.Mn4Ni and Mn4Pd cluster possess a larger ferromagnetic alignment of 20μB,which cause it the most promising cluster.The variations of the magnetic properties resulting from different dopant atoms are also exposition in this paper.