By using the soil moisture data of Heilongjiang Province from 1981 to 2010, selecting the Fujin county of the east, Longjiang county of the west, Shuangcheng county of the south, Heihe city of the north, and Hailun county of the middle in Heilongjiang province, the trends of soil moisture during winter and the drought wet change are analyzed, and the significance tests are conducted with three methods: linear trend, 5 year moving average, and Mann Kendall. The mutation test of soil moisture change is made with Mann Kendall and Yamamoto methods. The results show that the soil moisture at the depth of 0 to 30 cm underground showed various downtrend in the last 30 years: the decreasing of the soil moisture at the Longjiang county was the sharpest, Hailun county the second, and Heihe city and Shuangcheng county the next; moreover, the significance levels of soil moisture decreasing at 20 cm for all the stations were lest than 005, but the decreasing at Fujin county was slight. The results of the Mann Kendall test show that there appeared mutational zones in Longjiang and Hailun counties, and the downtrends of the other stations were close to, or exceeded the significant level in the recent years. The mutational time of soil moisture change was 1994 for the soil layer of 0 to 20 cm in Longjiang county. The decreasing of winter soil moisture in Heilongjiang Province is related to temperature and precipitation, as well as the deterioration of the soil physical properties.