Nanoparticles of CuInSe2 (CIS) were synthesized by pulsed laser ablation. The effect of the preparation conditions on the structural properties of the CIS nanoparticles was investigated. The CIS nanoparticles showed a more developed structural property after treatment in Se-evaporated atmosphere. By X-ray photoelectron spectroscopy, increase of Se amounts in the CIS nanoparticles was confirmed. Enhancement of phonon modes in the CIS nanoparticles was observed in Raman scattering spectroscopy while secondary phases like In2Se3 or CuAu structure-related peak were identified in the spectra. High-resolution transmission electron microscopy indicated that the individual nanoparticles were embedded in matrix of some amorphous layers and diffraction patterns representing the chalcopyrite structure were also scrutinized.