Molecular dynamics study has been carried out for nucleation in supersaturated vapor of carbon dioxide. The molecular model is of Lennard-Jones (LJ) + Coulomb type proposed by Murthy et al. [C.S. Murthy, S.F. O'Shea, I.R. McDonald, Mel. Phys. 50 (1983) 531.] and molecular dynamics simulation is within an NEV ensemble. Detailed analyses have been performed for the cluster size distribution, percolation phenomena, reaction rates and equilibrium constants of nucleation, and others.