The objective of this study is to analyze the effects of increase in the oyster hatchery on fishermen`s income. The results of the analysis are as follows : ①The necessary quantities of oyster seed are 18,000 thousand hanging line. The 29.4% of that has been applied by ana-seed collection and 29.1% of that has been applied by proceed collection. The demage of oyster aquaculture business is estimated about 35 billion won or 83 billion won. ②The production cost per hanging line of the oyster hatchery is 1,974 won. And if it is sold by 2,500 won, return on investment will be 31.9%. Therefore profitability of the oyster hatchery is very good. ③There are four important determinant variables of profitability to the oyster hatchery. In the order of their effects, it is operation number, seed price, production cost, and quantity of production. ④If differences of price between the artificial hardening oyster seed and the natural hardening oyster seed are more less 1,430 won, the former is better. ⑤The necessarily quantities of the oyster hatchery are estimated 160 units in the scale of 10,000 hanging line production to one operation. ⑥The effect of increasing income of fishermen are estimated about 85.3 billion won or 124.5 billion won from increase in the oyster hatchery.