Jinhae Bay is a typical aquaculture farm with active fisheries. However, it has been contaminated by the development of a major city and industrial area, and has therefore diminished in value as a fishing ground. To preserve the continuing productivity of the ocean, we have to estimate fisheries resources. To analyze the fisheries resources in Jinhae Bay, we evaluated the Fisheries Productivity Index (FPI). The FPI is composed of the Total production ($T_p$), Total amount ($T_a$), and Production of edible protein ($E_p$), nitrogen ($N_p$) and phosphorous ($P_p$). To calculate the FPI, we used Annual statistics on cooperative sales of fishery products data from 1979 to 2004 and the Food composition table. The results of the FPI were as follows. $T_p$ ranged from 70,235 tons to 113,556 tons and $T_a$ ranged from 107,004 million won to 373,776 million won. $E_p$ ranged from 8,124 tons to 13,357 tons, $N_p$ ranged from 1,965 tons to 3,273 tons, and $P_p$ ranged from 168 tons to 276 tons. According to the FPI, maximum fisheries productivity occurred in 1994, when $T_a$, $E_p$, $N_p$ and $P_p$ were at their highest values.