Offshore Wind Turbine (OWT) is a device to extract and convert offshore wind energy into useful electrical power. The typical concept design of monopile foundation structure for 1.5MW OWT is raised in this paper. The arrangement of the monopile and related accessorial facilities are especially considered during design. Mechanical characters of the foundation structure are emphatically analyzed, including static analysis, dynamic analysis, fatigue analysis and bucking analysis. The time domain approach is preferable for the dynamic response of foundation under the condition of earthquake and wave. Based on the analysis results, the reliability of the structure is proved to be satisfied with the requirements .The paper provides the reference for the design of OWT.