Molecular dynamics simulation has been conducted in order to obtain the fundamental understanding for the formation mechanism of CO2 clathrate-hydrate that suppresses the dissolution of liquid CO2 isolated at deep ocean floor. It was demonstrated that the H2O molecules formed a characteristic cage structure of type I clathrate around the CO2 guest molecules after 260 ps from the initial condition of H2O molecules at pressurized water state. CO2 clathrate-hydrate formation kinetics has elucidated that the interactions between the CO2 guest molecules would form a low potential region, which has an effect to suppress the H2O molecules motions in a two-dimensional plane and assist to form cage structures consisted of 5 and 6 membered rings.