Renewable energy is attractive research issue. Especially, one of the most popular resource is wind energy because wind energy is relatively sustainable and nonpolluting. Recently, wind energy power increases dramatically in Europe, Japan, China and USA. Existing bottom fixed types have many limitation and problems such as the limitation of installation site, noise and so on. However, it is possible to solve these problems by using floating type wind turbines. To design optimal offshore floating wind turbine, numerical analysis tools must be used. Also these analysis tools must predict loads and motion of wind turbines. considering complex environmental phenomenon. In this research, blade element momentum theory (BEMT) is used to calculate the aerodynamic loads and time domain potential theory is used to calculate the hydrodynamic response. Aerodynamic analysis module and hydrodynamic analysis module is developed individually at each department. Therefore, appropriate coupling method is used to calculate fully coupled aero-hydrodynamic response. In this research, partitioned coupling method is used, especially staggered solution procedure. Implementation procedure of analysis module will be explained and verification of analysis code is described.