Formation and vibrational states in nanoparticles have been investigated by means of molecular dynamics simulation. The embedded atom method potentials for Cu and Au were adopted to express the interaction between atoms in the crystals. The nanoparticies were formed by cooling the atomic systems of molten states. Surface morphology of the nanoparticles were represented by highlighting the surface atoms which were distinguished by the potential energy. Simulated surface morphology is not so symmetric as natural nanoparticles. The radial distribution function and the cross sectional view of the particles were also derived to characterize the internal structure. Thermal vibration of sample atoms at elevated temperatures was analyzed and the power spectra were calculated. Excitation of phonon mode is seen in the spectra.