Based on sea ice concentration data of NSIDC and AMSR-2, the spatial and temporal variation characteristics of the Maud Rise Polynya (1973, 1980—2017) and the Weddell Polynya (1974—1976) occurred in the Weddell Sea from 1972 to 2019 were analyzed in order to provide a basis for the study of their formation and long-term variation mechanism. Choosing sea ice concentration of 40% as a threshold to determine the polynya area, it is found that the Weddell Polynyas (average area of 250 000 km²) lasted from the freezing to melting seasons, while the Maud Rise Polynyas(from 1 350 km² in 1980 to 53 180 km² in 2017)appeared relatively late(later than July 18) and lasted for a much shorter period(from 3 days to 23 days, except for more than 90 days in 2017).These spatial and temporal characteristics reflect the remarkable differences in the convective activities associated with the Weddell Polynyas and the Maud Rise Polynyas. In addition, based on the floating data, the ocean temperature and salinity properties in the regions where the polynyas appeared in 2016 and 2017 were also analyzed. It is found that the surface water salinity increased in the summer of 2016, and became warmer and saltier in 2017, but fresher in 2018. These processes may be closely related to the occurrence of the Maud Rise Polynya in the winter of 2016, the increasing of its area in 2017, and the absence of it in the winter of 2018. Besides, in 2019, a new polynya, which had never appeared yet, formed in the region (66°~69°S, 24°~36°W) to the southwest of the Maud Rise, and storm may attributed it.The ocean and atmosphere play an important role in the occurrence, maintenance and disappearance of polynyas.