Environment is one of the main factors which influences the physiological characters. By changing the growing environment of plants to study the change of plant physiological characters is the hotpot of physiological ecological research, while high altitude areas with vary environments provide a good condition for the study of species to adapt to new environments. This research compared the light response parameters, spectral reflectance, and spectral reflectance indices of three Betula platyphylla seedlings from different altitude and a single common altitude on the Changbai Mountain by means of transplanting ages from 3 to 5 years of Betula platyphylla seedlings from altitudes of 750 m,1200 m and 1400 m to the same altitude of 750 m to analyze the differences and similarities of physiological and ecological characteristics between the initial stage and 1 year after transplantation, and to explore the adaption of Betula platyphylla seedlings to the new environment. The research showed that by comparing the physiological characters among different sources of elevation of Betula platyphylla transplanting seedlings as well as wild Betula platyphylla seedlings of the original elevation, the physiological traits of different Betula platyphylla seedlings including net photosynthetic rate(A_max), stomatal conductance(G_s), and intercellular CO₂ concentration(C_i) were significantly different(P < 0.05) and spectral reflectance index were also significant difference(P < 0.05) in the early of transplantation.After a growing season, the physiological traits between Betula platyphylla seedlings from different altitudes and Betula platyphylla seedlings from situ altitude of 750 m were not significant difference (P > 0.05), as well the spectral reflectance index (P > 0.05), but the physiological traits between Betula platyphylla seedlings from different altitudes and Betula platyphylla seedlings from situ altitude of 1200 m and 1400 m were significant difference (P < 0.05), Similarly, there were no significant differences in spectral reflectance index(P < 0.05).The research shows that various physiological indicators of Betula platyphylla seedlings had changed due to the change of environment, but seedlings still retained the original physiological characteristics of the situ wild Betula platyphylla seedlings in the early of transplanting; After a growing season, the transplanting Betula platyphylla seedlings gradually adopt to the new environment and the related physiological characters has changed, which means the physiological characters of the transplanting Betula platyphylla seedlings have convergence with the wild Betula platyphylla seedlings. By comparing the change of physiological characters before and after the growing seasons, the research shows that as a pioneer plant, when Betula platyphylla seedlings transplant to new environment, they are highly adaptive to their environment, which means they can adjust the physiological characters to adapt to the new environment. The significance of this study is to provide reference significance for succession of seedlings and forest regeneration.