The multiply twinned particles (MTPs) of Cu, Ni, Ag, and Pd formed on an electrode in solution at low electrode potentials were systematically studied by means of transmission electron microscopy (TEM). At low electrode potentials the icosahedral and dedahedral particles were observed for gold, silver, and palladium, but only the decahedral particles were observed for copper and nickel. The icosahedral particles of copper and nickel are less stable compared to the decahedral particles. The decahedral Ag particles were oxidized during the observation by TEM and changed into Ag2O having fee structure. The stability of these transition metal MTPs formed in solution is in the sequence Au > Ag > Cu and Pt > Pd > Ni. The differences of d-s hybridization or s,p-d hybridization among 3d, 4d, and 5d transition metals will increase the surface electron density, which results in the contraction of the lattice in the lateral direction. The decahedral and icosahedral particles of Au were formed on an SnO2 electrode, which indicates that the MTPs of Au are grown not only on carbon film but on SnO2 film depending on the electrode potential.