Abstract: According to the classification system of life-form provided by Raunkiaer,the life-forms of 290 vascular plants of 10 Quercus mongolica communities in north-east China were analyzed.The results showed that the hemicryptophytes were the dominant life-forms,accounted for 32.4% of all the forest vascular plants,followed by geocryptophytes,accounted for 23.1%,mesophanerophytes and nanophanerophytes were about 14.6% and 13.9% separately.Altitude and latitude could affect the ratio of geocryptophytes.With the increasing of altitude and latitude,the ratio of geocryptophytes had a trend to develop.The regression analysis among geocryptophytes,hemicryptophytes,altitude and latitude were done.The water content in soil could affect the ratio of therophytes.The ratio of mesophanerophytes,nanophanerophytes,hemicryptophytes and chamaephytes didn't change significantly with the increasing of altitude and latitude.

Key words: North-east China, Q.mongolica communities, Vascular plants, Life-form spectrum