Based on the observation data from 15 agro-meteorological stations from 1980 to 2014 in Heilongjiang province,By using of the active accumulated temperature anomaly ≥10 ℃ index for assessment of cold damage to maize in Northern China,this paper estimated the occurance of maize clod damage during seeding emergence and seven leaves period,during seeding emergence and tasseling period,during seeding emergence and milky maturity period,and the temporal and spatial distribution of cold damage were analyzed. This paper investigated the relationship between active accumulated temperature anomaly ≥10 ℃ and maize yield. The results showed that the sum of maize cold damage year is from 7 to 17 in the three critical development period during 1971 to 2014,and the occurance of cold damage is consistent with climate warming trend. The frequency of cold damage year decreased and its appearance was high from 1980s to the middle 1990s. In whole study area,the frequency of cold damage year in North was higher than that in South areas,and the occurance of cold damage showed the clustering,regional and local characteristics. From 1980 to 2014,the period of active accumulated temperature anomaly ≥10 ℃ was about 16 years in a large scale,and the temperature was low before 1995 and it was warming after 1995,but during seeding emergence and seven leaves period,it had been cold in the recent years in a small scale. Correlation between active accumulated temperature anomaly ≥10 ℃ and maize yield was significant in agricultural meteorological station from 67% stations,active accumulated temperature anomaly ≥10 ℃ was 100 ~ 200 ℃·d which was favorable to maize yield. Active accumulated temperature anomaly ≥10 ℃ indicated the biology and agronomy meaning of maize cold damage index,it showed the relation of heat supply and demand,which improved the objectivity of assessment of cold damage to maize.