Abstract: In-situ measurement of bridge foundation located underwater sediment soft clay and sand by using GA pressuremeter is introduced. The results of test show that it is linear relationship between the ground bearing capacity calculated by pressuremeter test and standard penetration test(SPT). The increasing degree of the ground bearing capacity of hard stratum is slow with the increasing of N_63.5, but that of soft ground is fast with the increasing of N_63.5. It can be well used for nicety ascertaining the ground bearing capacity by SPT and partial pressuremeter test data and determining the position of supporting course.