Abstract: Piles are usually adopted as the foundation for platform location at Chengdao oil field of the Yellow River delta. The operation will disturb submarine geomorphology and structures of shallow sediments during pile pitching and pile pulling out. As the result, the engineering properties of foundation soil will be changed after refilling. Based on the results of water-depth measurement and data from shallow profiling, we made comparison of engineering geology conditions before and after pitching piles in this paper. The origin of the changes is also discussed.