Abstract: In this study， several indexes of seed germination， seedling growth and physiological characters in balsam pear were investigated under low （13℃） and sub\|low （20℃） temperature with cerium nitrate treatment. The results showed that seed germination and seedling growth were inhibited under low and sub\|low temperature compared with normal temperature （30℃， control）. Germination potential， germination rate， vigor index and activities of dehydrogenase and α\|amylase were increased significantly when seed was soaked with 9214 mmol·L-1 Ce（NO3）3·6H2O under low and sub\|low temperature， meanwhile proline（Pro） content and soluble sugar content also were increased. On the contrary， membrane permeability and malonaldehyde （MDA） content were decreased remarkably. In conclusion， seed soaking with 9214 mmol·L-1 Ce（NO3）3·6H2O could promote seed germination and seedling growth under low and sub\|low temperature condition.

Key words: balsam pear, cerium nitrate, low and sub\, low temperature, seed germination；physiological index