Abstract: A 1∶100000 coastal marine geological environment and geological hazard investigation was carried out for the first time in the Pearl River Delta, one of the most important economic zone in China, basing on integrated method of remote sensing, hydrology and hydrochemistry, comprehensive geophysical survey, geological sampling, geological drilling, and static sounding. The chemical parameter of seawater, marine environmental quality, hydrodynamics, topography and geomorphology, sediments, shallow stratigraphic structure, potential geological hazards and submarine engineering geological conditions were analyzed, and the marine geological environment was assessed and forecasted. Finally, reasonable suggestion about coastal marine development and engineering construction were put forward.