Polynyas accelerate oceanic and atmospheric processes. We additionally think polynyas influence biological activity. We pursued daily transition of polynyas in the Ross Sea, Antarctica from 1978 through 1994 using images of sea ice concentrations by the satellite microwave observations. A typical polynya existed in the inner area of the Ross Sea in November of the each year. The shape of the polynya changed remarkably in several days. The polynyas have the range of approximately 500 km from the bottom to the entrance of the Ross Sea. The polynyas usually open to the northern oceanic water late in December in each years except 1982, 1988 and 1992.