Abstract
So far, for pearl culture using abalones, a plastic nucleus has been planted in an abalone by perforating the shell. But after planing 80 % of abalones died, and even if they live, the pearl's hardness was not so good. The weak hardness made the pearl valueless. The quality of a pearl is decided by the gloss and the quality of the pearl's layer. This study is to find the right nucleus for abalones and to decrease a death rate of abalones by selecting the right planting place. This study was also performed to obtain valuable pearls with proper size, gloss, and good color. Below is the result of the research; Conch shells out of the various nucleus materials were the best. Their shape, color and gloss were very good. The nucleus was planted in the part that a shell is grown up under the absorption ball, as a result a pearl sack was quickly made. After 15 days, out of every pearl, pearl sacks were made. The pearl formation was measured every month. From the abalone shell which was planted in April, qualitative pearls which was from 5mm to 5.81mm in size were obtained in December.