It is hard to find an operation case using anti-submarine searching pattern(ASSP) developed by Korean navy since Korean navy has begun submarine searching operation. This paper proposes the method to develop hull mount sonar(HMS) based optimal submarine searching pattern by using genetic algorithm. Developing the efficient ASSP based on theory in near sea environment has been demanded for a long time. Submarine searching operation can be executed by using ma ulti-step and multi-layed method. however, In this paper, we propose only HMS based ASSP generation method considering the ocean environment and submarine searching tactics as a step of first research. The genetic algorithm, known as a global opination method, optimizes the parameters affecting efficiency of submarine searching operation. Finally, we confirm the performance of the proposed ASSP by simulation.