A great part of electric power generations from renewable energy is contributed by offshore wind energy. The site development plan, which is specified in the German Offshore Wind Energy Act, will be the essential guideline for the construction of offshore wind turbines and offshore connection lines in the future. Furthermore, the two current plans will be replaced by the site development plan. Besides construction, the plan also contains the economic contents of bidding. As the foundation for all planning steps, which are necessary for a new installation of offshore wind park, this plan connects all the planning processes entirely. Therefore, it has more advantages than the other two plans to achieve the goal of extended construction for offshore wind turbines. This article describes the detail of the site development plan, including its objects and formulation. Its significance for the subsequent planning steps is also investigated.