Abstract: This work was started in April,1954 and completed in July,1957. The characteristics of four species of eucalyptus and its ecological conditions are dis- cussed,and the observational methods and the phenomenal periods of phenology are par- ticularly emphasized.The phenomenal periods of phenology are divided into four major periods,namely:1.budding period:2.the ripening of buds 3.the bloomming period and 4.fruiting period.Eight minor periods are further divided such as:1.budding period 2.the formation of buds;3.the ripening of buds 4.the falling-off of opercule; 5.the withering of androecium;6.the withering of gynoecium 7.the formation of capsulo;8.period of capsule ripening.