Gravity surveys were carried out on Ross Island during the austral summer of 1982-1983. Twenty-one gravity stations were established in the summit area of Mount Erebus and eleven stations in the other area of Ross Island. The Bouguer gravity anomaly distribution shows a possibility of the maximum positive anomaly in the northeast side of the Erebus main crater, though the gravity stations are sparse there. This might be due to the fact that the structure of Mount Erebus is not a caldera type but nearly of the same type as the Kilauea Volcano of Hawaii Island and the O Sima Volcano of Japan