Abstract: In the Oujiang river estuary area, there is a big risk in the laying and being operated safely of submarine pipeline. The conventional method to test can't be used because of the strong tide and obvious shoal water. This paper uses sub-sea acoustic technology of side scan sonar to explore seafloor landform of the area where submarine pipelines go through effectively. Natural microrelief includes flat seafloor, large sand ridge, tidal creek, small pit, and alteration bulge. Anchor ditches are formed by dropping anchor and secondary microrelief developed naturaly later. They all are found and analysed. The result has an important significance to propose the corresponding solution countermeasures to different kinds of seafloor landforms and to reduce the topographic form influence on the stability of submarine pipeline.