Abstract: The Diameter Breast-High( DBH) structure and their mathematics model of several main trees in Tilia broadleaved Korean pine forest were studied in this paper. The results showed that DBH of 30cm took an important place in the communities, Fraxinus mandshurica had the biggest DBH and Pinus koraiensis was the second. There are many DBHs between 25cm and 75cm. Acer mono has less DBH and younger age. The growth model of trees showed that the yield was positive correlation with DBH. DBH and the yield increased with the age being old. The results could provide theorical basis for forest cut and forest management.

Key words: runoff washout, water flow velocity, runoff kinetic energy, unit runoff energy consumption, hydrodynamics parameter.