Abstract: After 4℃ low temperature stress,the content of soluble protein,soluble sugar,proline and water on different phonological period of Ledum palustre L.subsp.decumdens was measured.The result showed that the phenological period C has different physiological adaptive mechanism for low temperature stress.Under low temperature stress,L.palustre L.subsp.decumdens in germinative period shows stronger hardiness.The content soluble protein,soluble sugar and proline increased and maintained at a high level.If the L.palustre L.subsp.decumdens is growing or reproducing,it has weak hardiness.During low temperature stress the three physiological parameter decreased first.When the physiological adaptive mechanism to low temperature stress has been formed,the physiological parameters increased again.In the three phenological period,The Ledum palustre L.subsp.decumdens content of water maintains stability level,the content of bound water increased.

Key words: Ledum palustre L. subsp. decumdens, low temperature stress, phenological period