Poorly formulated initiatives on the port planning strategy are have negative effects on the tropical coastal zone. To reduce these effects, it is important to consider and analyze several scenarios of management plans in view of the major issues of the host territory. It allows to involve a range of actors in a decision-making process. A Strategic Environmental Assessment Process for a Harbor Development Plan is proposed from a Literature Review and Expert Consultations. It includes 7 steps based on decision-making multicriteria tools and geographic information systems. The design is based on the contribution of various actors in order to make better choices. These choices can be made on the basis of ecological, social-economic and technical criteria.