In the stock assessment of fisheries resources, the spawning stock abundance is important rather than the total biomass including immatures. However, the future stock depends on both matures and immatures. We propose a stock assessment method using "population reproductive potential (PRP)" that are defined as the sum of reproductive valus of all individuals, and we propose a management strategy based on PRP. In addition, fish prices per body weight may vary with ages, seasons, and fisheries. We propose the fisheries management strategy that uses the harvest values to maximize the catch yield. In addition, we try to extend the concept of reproductive value and harvest value to snow crab, which male has a high price, and to pink shrimp that shows protandry.