One-year-old cut dormant branches of‘Shushanggan’apricot was put at -20℃,-25℃,-30℃and -35℃.The treated branches were cultured in water and their germination and flowering number observed and recorded.Their electrolyte leakage was determined using electronic conductance method.The results showed that at -25 to -35℃,electrolyte leakage rate increased as the temperature drop.When it below -30℃,the electrolyte leakage rate increased significantly and germination rate declined seriously.The comprehensive test results showed that the critical temperature was about -25- -30℃.