Abstract: 137Cs tracing of 7 cores of undisturbed columnar sediments taken from the sea area on both sides of the seawall of Huanghua Harbor shows that there are three types of 137Cs distribution curves: ① discontinuous curve (no 137Cs is detected at the surface); ② continuous curve (137Cs is detected at the surface); and ③ curve along which no 137Cs is detected. Modern sedimentation rates traced by 137Cs shows that: ① after the SE-trending coastal currents were cut off by the seawall of the NE-trending harbor, there occurred differential modern deposition on the two sides of the seawall of the harbor, i.e. the modern sedimentation rates in the sea area less than ~4 km deposit near site 8 away from the shoreline on the northern side of the harbor seawall are notably higher, 0.69~1.12 cm/a, whereas no sedimentation in the sea area 4 km away from the shoreline on the southern side of the seawall; and ② a modern depocenter with a sedimentary rates of up to 1.36 cm/a exists at -4 m water depth 10 km off the shoreline on the southern side of the seawall. A comparison between the above-mentioned results and the previous work results indicates that the geo-environmental changes closely related to human activities dominate the current geo-environmental changes, to which more attention should be paid.