Abstract: Based on the dataset of daily mean temperature from 1961 to 2010 in 70 meteorological stations of Heilongjiang province,the starting date of maize sowing time,the spatial differences of climatic trend rates,and the latest sowing time of current varieties and relief varieties were analyzed by using GIS software and statistical methods The results indicated that the starting sowing date of most maize in Heilongjiang province was during late April and early May This date in most parts of Songnen plain was from 22 nd April to 5th May and in Sanjiang plain and local area of Mudanjiang was from 26th April to 5th May, while the date changed from 6th May to 20th May in other areas In the past 50 years, the average trend of maize sowing time in Heilongjiang province was not obviously, but in some parts, the starting sowing date was significantly ahead of the average trend,especially in Heihe and Qiqihaer For current  varieties ,the latest sowing date of late-maturing ones was middle May,and this date of maturing varieties was at the beginning of late May in Songnen plain While in Sanjiang plain and Mudanjiang the latest sowing date of maturing ones were at the end of late May,and early-maturing ones were at the beginning of late May In addition, the latest  sowing  time of relief varieties tended to delay from north to south, the date changed from 1st June to 23rd June In most parts of Heilongjiang province this period was 11-15,June This study provided evidence that climate change could affect  maize sowing time, and the results can be used to protect maize from potential risk

Key words: Accumulated temperature, Starting date of maize sowing time, Latest sowing time, Climatic tendency rate