The instrumental earthquakes data during 1905∼1982 of the Korean Peninsula were investigated and analyzed. The annual average frequency is 5.7 events and the return period for all events is 0.18 year. In the pattern of annual frequency, the recent seismicity of the Korean Peninsula has tended to increase since 1975. Most earthquaked occurred in the southern and western part of the peninsula, and along the major geologic structure lines such as faults, fault lineaments and fold belts, especially in the NE-SW strike structure lines. Many earthquakes occurred at places where the Bouguer gravity anomaly is positive, especially in the high anomaly gradient considered as rock boundary. Over half (51.4%) of all events in land occurred in the Precambrian metamorphic rocks, which are granti-gneiss and crystalline schist system. And a tentative seismic zoning map is presented.

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