One skin diving and four SCUBA divings were made by two members (a biologist and the author, the physiologist) of the 9th Japanese Antarctic Research Expedition on 2 February in 1968 for surveying benthos. They dived about 10 metres at Lang Hovde, about 20km south from Syowa Station, Antarctica. Air and surface water temperatures were about 0℃ and it was calm. Neoprene double wetsuits of 5 mm and 6.5 mm in thickness, covering the whole body except face, were used. It took 49 minutes in total. The pulse at the end of skin diving recorded 130-140/min. One diver lost 2 kg weight after diving, but the other showed no change. Erythrocytosis, eosinopenia (91% and 72%) and lymphopenia caused by stress were observed. There were no remarkable physical changes except for mild epistaxis and light headache soon after diving.