Abstract:Heilongjiang Province is located in the northernmost part of China, with the lowest annual mean temperature all of the whole country, which belongs to the cold region of rice cropping. The chilling tolerance in bud stage affected the emergence rate of rice. In order to determine the distribution of chilling tolerance in bud stage of some rice Cultivars in Heilongjiang Province, 38 varieties of Longjing series and two varieties of Hejiang series were selected to evaluate chilling tolerance in bud stage. The results showed that 20 of the 40 varieties had strong chilling tolerance in bud stage, the strongest varieties were Longjing 10 and Longjing 25, the dead seedling rate were both 9.33%, and 11 varieties with moderate chilling tolerance in bud stage. There were 9 varieties with weak chilling tolerance in bud stage, among which Longjing 40 had the weakest chilling tolerance and the dead seedling rate reached 90%.