Abstract: According to the observed data，we established the models for stand growth，yield forecast，stand density effect and hydrological function prediction of Masson pine forest for water and soil conservation．On the basis of these，applying the principle that forest function depend on the stand structure，combining the mathematic method for plan opti-mization and the means of computer simulation，we developed the simulation software for managerial regulation of Masson pine for water and soil conservation，and the opti-mal managerial strategy of Loropetalum chinese-Pinus massoniana forest was presented，which fits to various managerial purposes．The results indicated that with the increasing of stand diameter，tree height and biomass，the capacity of stand retaining rainfall and conserve water increased，whereas the earth's surface runoff and soiI erosion module de-creased，and the integrative grade of water-holding function increased correspon-dently.While there are larger differance in biotic yield and hydrological benefit at the same site with different managerial purposes．

Key words: Masson pine, Forest for water and soil conservation, Managerial regu-lation．Simulation