We have developed a three dimensional Haasen-Alexander-Sumino model to investigate the distribution of dislocation density and residual strain in Si crystals and compared the calculation results with experimental data performed in mono-like and multicrystalline silicon ingots. The results show that the residual strain in a multicrystal is lower than in a mono-like crystal, whereas the dislocation density in the multicrystal is higher than that in the mono-like crystal. This phenomenon is due to the relation between dislocation density and residual strain caused by the difference of activated slip systems in a mono-like crystal and a multicrystal.