Refueling is one of essential methods in order to control plasma density and sustain steady state plasmas. A gas puffing has been successful for building and sustaining a plasma density in an experimental system of past generation. However, in a large scale experimental system, e.g., LHD, the plasma sources induced by the gas puffing are strongly localized near the plasma surface. Then, a pellet injection is placed as a fundamental tool and has been mainly used to obtain a high density plasma and control a density profile. When a pellet consisting of solid deuterium is injected into torus plasma, it is heated by an energy flux in the plasma, and it changes to vapor though phase transition and subsequently to plasma through atomic processes. A new type of a MHD code applicable to solid, liquid and gas states, "CAP" has been developed in order to investigate an ablation process of pellets in hot plasmas under various atomic processes. One of the most important features of the code is to be able to treat recession of the pellet surface by ablation without any artificial boundary condition between the pellet and ablation cloud. In the present work, the ablation cloud consists of molecules, atoms, ions and electrons. Dissociation and ionization in the ablation cloud are considered by assuming local thermodynamic equiriblium. The heat flux from the bulk plasma is carried by the incident electrons which the distribution of energy is taken as a Maxwellian. In result, a shock wave is found to be driven by ionization in the ablation cloud because the ionization reduces expansion of the cloud. Though dissociation dose not drive a shock wave, it induces a plateau region in the ablation cloud. These atomic processes have much effect on spatial profiles of the ablation cloud, but little effect on the ablation rate and pellet life time. Nonuniform ablation pressure induced by anisotropic heating along B-field leads to a deformation of the pellet, so that the pellet life time is found to be shorter than one predicted by an ablation model. When J × B force is considered, a magnetic well is constructed around the pellet due to ablation pressure that is several MPa. On the other hand, a magnetic hill is constructed as surrounding that well. Then, those magnetic field disturbs the heat flux from the bulk plasma and reduces the ablation rate. The ablation rate and pellet life time will be evaluated with those effects in the present work.