[en] We investigate the Hugoniot curve, shock–particle velocity relations, and Chapman–Jouguet conditions of the hot dense system through molecular dynamics (MD) simulations. The detailed pathways from crystal nitromethane to reacted state by shock compression are simulated. The phase transition of N_2 and CO mixture is found at about 10 GPa, and the main reason is that the dissociation of the C–O bond and the formation of C–C bond start at 10.0–11.0 GPa. The unreacted state simulations of nitromethane are consistent with shock Hugoniot data. The complete pathway from unreacted to reacted state is discussed. Through chemical species analysis, we find that the C–N bond breaking is the main event of the shock-induced nitromethane decomposition. (paper)