In this study, four densities 3, 6, 9, 12 ind./liter (L) were experimented in orqer to identify a suitable density for rearing triploid Pacific oyster from the stages of fry to fingerling. Results showed that absolute growth rate and relative growth rate of the oyster reared at the density of 3 and 6 ind./L were significantly higher than those of the density 9 and 12 ind./L (p 0.05). However, there were no significant differences about these parameters within the densities of 3 and 6 ind./L or 9 and 12 ind./L (p 0.05). The survival rate of the oyster reared at density of 3 ind./L was higher than those of the densities 9 and 12 ind./L (p 0.05), however, there was no significant difference about survival rate between the densities of 6 and 9 ind./L (p 0.05). From the results of this study, it can be suggested that the appropriate density for rearing the triploid Pacific oyster from the stage of fry to fingerling was from 3 - 6 ind./L in order to optimize the growth, survival rate and tank rearing squares.