Abstract：The cold tolerance of 22 cucumber（Cucumis sativus L.）cultivars belonging to 6 different ecotypes was evaluated and the relative germination ratio of seeds under 15 ℃，radical growth rate under 2.5 ℃ treatment and relative electron leakage ratio at seedling stage of each cultivar were tested．The results indicated that two out of 8 North China cucumber cultivars showed strong tolerance to cold stress and 1 was tolerant to cold stress．4 South China cucumber cultivars were sensitive or low tolerant to cold stress．Nine cucumber cultivars belonging to American field type，European greenhouse and field types were of different eco-types，showing tolerance，mid-tolerance and no tolerance to cold stress．Only 1 Japanese cultivar was sensitive to cold stress.
