Marine deposit soft clays are often encountered in marine traffic engineering. Their vane shear strengths are important parameters for verifying stability of foundation and slope. However, the marine vane shear test is affected by many factors, such as wind wave and tide, thus it is difficult to implement. Moreover, related research about test data is limited. Based on the results of the marine vane shear test of soft clays in various harbor locations, correlation between test results and effective gravitational stress and SPT counts is analyzed and corresponding equation is built. This is very useful for the application of the marine field vane shear test to soft clay.