This paper presents a design support system for basic design of ships. The system aims at supporting designers by presenting documents needed for each task according to design processes. In order to construct our system, several approaches were adopted. At first, an analysis of basic design process using UML was made. Authors understood its workflow and extracted a data list to make documents for each step of the workflow. Secondly, Semantic Web architecture was introduced to structuralise ship design documents. By applying Semantic Web technology, users can query to collections of documents as if using relational databases. Authors implemented the system and evaluated it through an example of basic design. The system shows its efficiency in the evaluation.