Based on the daily minimum and average temperature data of 162 meteorological stations over the Northeast China from 1961 to 2014, the characteristics of the first frost date, the last frost date and the frost-free period in recent 53 years in Northeast China are analyzed. The results show that: the average date of the first frost and the last frost is September 28 and May 5, the average frost-free period is 145 d. Among the 162 stations in Northeast China, there are 155 stations where the first frost date became later, and there are 160 stations where the last frost date became earlier, and there are 158 stations where the frost- free period had been prolonged during the past 53 years. The first frost date has significantly delayed at the rate of 1.55 d/10 a, the last frost date has moved up at the rate of 2.51 d/10 a, and the frost-free period has prolonged at the rate of 4.08 d/10 a over the past 53 years. The changing characteristics of the frost reflects the climate warming (0.3 ℃/10 a). Along with the increase of the latitude and the altitude, the first frost date became earlier, the last frost date became later and frost- free period became shorter. The influence of the minimum temperature is bigger than the influence of average temperature. The first frost date, the last frost date and frost-free period had abrupt change in 1986, 1989 and 1986, respectively. The mutation of the frost in the three provinces all occurred in the 1980s and 1990s. After the mutation, the multi-year average contours of the first frost date, the last frost date and the frost- free period in the Northeast China all pushed northward.