Abstract: Abstract：The Pearl River Delta Economic Zone, which lies in the central south of Guangdong Province and borders on the South China Sea, has experienced strong land-sea interaction and active neotectonism as well as obvious erosion，and is characterized by wide distribution of Quaternary sediments and a variety of landform types. It is a transitional zone and a sensitive belt of geological environment. The unique geological environment must have caused corresponding geological environment problems. Based on current survey and past research findings, the authors have summarized the main factors controlling geological environment, such as geomorpohologic landscape, neotectonism, change of sea surface and evolution of Quaternary sedimentation. The mainly problems of geological environment and calamity geology in the Pearl River Delta are put forward，which include earthquake and crustal stability，surface deformation in soft soil area，karst collapse，and coast anomalous change with the superimposition of sea level rising. From the angle of geological environment, some corresponding countermeasures are proposed.