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.

The graphic method has long been used by many authors in preparing site-class tables.But this tends to bring in the author's idiosyncracy as a source of errors.In the present paper,the least-squares method is adopted.

1.‘Water heartwood’which appears similar to false heartwood and red heart woo is the name applied to the central reddish-brown discorlored area in white birch(Betula platyphylla Suk.)