A sealing structure for sealing between a sliding roof and an opening portion of a roof panel of a motor vehicle. The sealing structure includes an annular frame member which is secured along the opening portion of the roof panel, an annular roof panel main seal for contacting a lower surface of a periphery of the sliding roof when the sliding roof is closed, and a roof panel sub-seal for contacting side edges of the sliding roof when the sliding roof is closed. The roof panel main seal and the roof panel sub-seal are attached to the annular frame member.