Based on the daily minimum temperature of 2 474 stations in China from 1960 to 2015, seven climatic regions were divided by REOF method. Regional averages of the thresholds of cooling extent of temperature over seven regions, seven cooling thresholds were obtained. The average temperature thresholds of the seven regions are different and get smaller from north to south, with a maximum decrease of 10.6℃ and a minimum of 7.6℃. The Cooling Extremes (CE) were defined and the temporal and spatial features of extreme cooling events in winter half year were studied. The results show that there is a significant spatial difference in occurrences of cooling extremes in the half year of winter, presenting a spatial pattern of occurrences with more occurrences in the north whereas less occurrences in the south. There are multiple centers with high frequency in the northern and two high-frequency zones around 42°N and 35°N. The occurrence frequency near 25°N is higher than in other parts of the south. Over the past 56 years, the CE frequency has a decreasing trend, which is more clearly seen in the earlier period. The spatial distribution of frequencies in each decade looks similar to each other. The abrupt changes in frequency of CE events are not uniform in spatial. In some regions, the time when the abrupt changes occur is earlier but in other regions later. These results can provide clues for deep understanding of the law of extreme low temperature events and climate prediction.