Abstract: Established in geologic evolvement of solum, relied on strong structural soft clay strata which belong to Zhanjiang Formation lower Pleistocene series the Quaternary system in Zhanjiang area, analyzed edimentation characteristic and engineering properties. It is found that Zhanjiang Formation is the deltaic-facies strata controled by river(interactive marine & continental sedimentation),and its special sedimentation characteristic result from multi-geologic-agent coupling action and strong tectonic movement effect. It is typical strong structural soil with higher structural strength result from agglutination, and its pedogenic evolutionary process is similar to that of laterite.