Abstract:This paper is a study on the phenology of the main tree species: Pinus koraiensis, Larix olgensis, Pinus sylvestris var. mongolica, Populus ussuriensis, Populus davidiana, Betula platyphylla, Quercus mongolica, Fraxinus mandshurica, Phellodendron amurense, Juglans mandshurica, Tilia amurensis, Acer mono, Ulmus propinqua of natural secondary forest in Northeast China. The main phenological character of these tree species are studied,the phenological spectrum of these trees is drawn and the relationship between the phenological period of the tree species and the environmental factors of light, temperature etc. is studied. It has been discovered that the meteorological factors which are most closely related to the germinating, growing and flowering etc. the main phenological periods, are total number of days of sunlight and the mean temperature of each period,showing that solar irradiation and temperature and their combined. effect are the important enviromental conditions of phenology,by the principal component analysis (PCA).Thirteen tree species are classified by clustering system according to the environmental factors of germination, growth period, flower period, the phenology date and the phenological type. The result are that there are 5 types of tree germination, 4 types of growth period, 4 types of flower period and 4 types of phenology date. Tree bionomic strategies, and a new concept of tree bionomic phenology strategies is also put forward through the analysis of the tree phenological types and the corresponding bionomic strategies of tree species.