The magnetic anomaly profiles across the Japan and the Yamato Basins are analyzed to find possible spreading centers. Magnetic anomalies are first transformed and then the correlation coefficient of symmetry of the pattern of profile is computed along each profile. If the coefficient of symmetry has a notable maximum at a point and such a point lines up for different profiles, the line of these points of maximum symmetry may be a spreading center. Three possible spreading centers are obtained. Two are situated at about the axis of the Japan and the Yamato Basins, and the other is at the topographic extension of the Yamato Ridge. The age of the opening has not been identified on the magnetic time scale yet, but the strike of the proposed spreading centers suggests a pre-Eocene time.