To arrange effectively artificial reefs for marine afforestation, tidal currents were analyzed by numerical experiments. The numerical experiments were carried out by EFDC(Environmental Fluid Dynamics Code), and water column was vertically divided 5 layers. Tidal current patterns showed to be affected by main current at outside of study area, and circle currents of two were observed from analysis of residual currents. The calculated harmonic constants of tide and tidal current agreed well with those of observations at two stations for tide and two stations for tidal current. The model successfully reproduced the tidal current around the Geomoondo marine afforestation. It suggest that artificial reefs for marine afforestation should be installed belt zone at study area.