Abstract: Since there is a lack of a cost-effective in-situ measuring approches in the beach and neritic area of special sedimentary envrionment, we developed a new core penetration test system in shallow sea areas(CPtss),devided into the main equipment composed of penetration device and hydraulic device and the auxiliary equipment composed of air filling device, vacuum generator, and system control device. In the testing process, the main equipment, after being draged to the target location by ship, measures sediment strength by hydraulic drive way, and records the strength parameters. The CPtss has been applied to the modern subaqueous Yellow River delta, and the variation of tip resistance, lateral friction, and friction-resistance ratio with depth was obtained, and the bearing capacity of seabed was caculated basing on the obtained sediment strength parameters, and the stratigraphic characteristics was analyzed. The developed CPtss introduced in this paper, with the charateristics of stable and easy operation, and the capacity of continuous navigation test, has a good application prospect in engineering-geology investigation in the beach and shallow sea areas.