In spite of remarkable developments about the research of the ocean wave, the properties of the waves in the closed sea area which are closely concerned with designing small ships are yet unknown. In this paper, the authors calculated the spectrum of the waves, and reduced the statistical properties of the waves nearly the course of small ships in The Seto Inland Sea. The observations were carried out with a pressure type wave recorder hanging under the buoy. And the objected area is about 25 miles square in size, and is almost isolated from open sea. So it may be affimirative that the waves are generated only by the window blowing over the area.. The results are represented in Table 4, Fig. 6, Fig. 7 and Table 9.