Kita-Kambara Plain has recently become one of the most active exploration and development area in Japan. Hirakida gas field is situated near the east boundary of this Plain. Narrow shelf area may be extending along the northwestern flank of the Kushigata Mountain range. Sedimentationa and truncation along the hinge line has large influence on gas accumulation of this field. Detailed structural and stratigraphic analysis may be neccssary to determine the most potential trend of this type of trap.