Two numerical models of water quality and egg/larva drift are prescribed. The fomer model can predict the distribution of velocity, Water temperature, salinity and dissolved oxygen in a nursery pond for flounders, Paralichthys olivaceus. This model will be a valuable tool for designing pond configuration and deciding reasonable inflow rate in comection with water quality. The latter model is based on Euler-Lagrangian method to take into consideration of spontaneous vertical movement of pelagic eggs and larvae of brown sole, Pleurronectes herzensteini. This model reveals the short-term wind fluctuation have a great effect on the transport and retention rate from the spawing to the nursery grounds in Sea of Japan and the vertical migration prevents the larvae from the dispersion to the offshore.