We study the effect of nucleation on chirality conversion induced by random fluctuation using a simple reaction model. The nucleation process, the crystal growth process and the dissolution process of crystals are considered. With the rate equation analysis, because of the nucleation process, one fixed point of the racemic state appears in the crystal mass space. With the master equation analysis, homochiral states may be realized, in which the effect of fluctuation wins the macroscopic flow that leads to the racemic fixed point.