he spatial and temporal variations of the frost seasons in the Heilongjiang province were investigated. the main resules are as follows: During 1960's and 1970's,the onsets of the frost seasons are earlier than normals,the ends of the frost seasons are later,and the frostless seasons are shorter; Since 1980's,the ends of the frost seasons have been gotten earlier and its onsets is later in the most parts of Heilongjiang province,thus the frostless season is longer. These show that the climate is colder than normals before 1970's,after that it is changed into warmer.