PROBLEM TO BE SOLVED: To provide a system for artificially creating a vegetation environment simulating the real site, predicting the result of the vegetation work and designing the optimum vegetation plan. SOLUTION: The greening simulation system 10 is provided with a vessel 38 having a top opening 48 and a material holding chamber 50 capable of holding a greening material 76, an angle adjusting device 12 to adjust the inclination angle of the vessel, an artificial sun light radiator 36 to radiate imitation sun light to the greening material held in the vessel having adjusted inclination angle, and a water-feeding apparatus 74 to supply water to the greening material held in the vessel. The simulation system can simulate the natural environment of the real vegetation site, predict the growing state of vegetables at the site, estimate the optimum amount of vegetable seeds to be sowed to dispense with the additional sowing and perform the vegetation work in high efficiency. COPYRIGHT: (C)2005,JPO&NCIPI