Recent frequent occurrence of urban sinkhole brings a need for the periodic inspection of sewer pipelines. Sewer inspection using a CCTV device needs a lot of time and efforts. Many of previous studies which have focused to reduce the laborious tasks are mainly interested in the developments of image processing S/W and inspection H/W. Nevertheless, there has been no attempt to find meaningful information from the existing CCTV images stored by the sewer maintenance manager. In this paper, we carried out a study about the construction of unfolding image of sewer video image. In general, the analysis results show that the image development is judged to have been well represented. It is expected to be a reference to the basic research of panoramic image.