Abstract: Detrended Correspondence Analysis is used to analyse the distribution of Korean Pine-broadleaved forest along the environmental gradients and the relation between varities of forest types and environmental changes. The results show that the integrated changes of various factors, such as water temperature and humidity in response to increasing altitudes in Changbai mountain,are the main gradient which decides the diversity of Korean Pine-broadleaved forest, the next is the changes of local topography and micro-topography. The technique of secondary ordination is applied to classify the Korean Pine-broadleaved forest and a classification system is given at the end of the paper.