It has been recognized that flow and mixing in industrial crystallizers have complex influences on the kinetics of crystal particle growth, dissolution, nucleation and agglomeration and, consequently, on the particle size distribution. In the present study, we performed a numerical analysis of the crystal particle motion in a stirred vessel by means of Lagrangian particle tracking in order to investigate the detailed particle motion, which affects the mass transfer rate from a particle. Further, the effects of instantaneous slip velocity and local solute concentration on the dissolution process of crystal particles were clarified. The results show that a detailed estimation of the instantaneous slip velocity and local solute concentration is necessary in order to accurately estimate the particle size distribution. It is also shown that the complete dissolution time calculated by this study based on the instantaneous slip velocity is shorter than that based on terminal velocity by a maximum of about 30%, mainly because of the centrifugal force. The numerical results were verified through dissolution experiments conducted under the same conditions as in the numerical analysis.