Source parameters of an earthquake with magnitude mb = 4.4 were determined by using surface waves. Small but clear surface wave signals were observed on long period records gathered from seismograph stations within an epicentral distance of about 2000 km. The focal mechanism was determined to be of strike-slip type with the maximum and the minimum compression axes trending NNW–SSE and ENE–WSW, respectively. The focal depth was determined to be near either 3 or 20 km.