The energetic particle event that occurred on 314 DOY in 2000 is a good sample to investigate particle acceleration mechanisms because both the coronal mass ejection and the energetic particles were observed. We obtained energetic particles using the stochastic differential equation method with the velocity of the shock wave and the assumptions of the energy spectrum of the input pre-accelerated particles and the diffusion coefficient. The behavior of the shock wave produced at a point on the

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... lar surface was obtained by hydrodynamic simulation. The simulation was carried out by the adaptive mesh refinement scheme in three-dimensional space. We tested the models of the diffusion coefficient. We concluded that the spectra at the time when the shock arrived at 1 AU agreed with the observed data but those at earlier times were small, and that the non-constant diffusion coefficient model, which gives an increase with the energy of the particles, cannot explain the low-energy component in the observed spectra. Therefore, the models of the pre-accelerated ambient particles and the diffusion coefficients should be improved.