Abstract: In the article, a new theory of forest structure, which eliminates the shortcomings of normal forest, generalized forest and regulated forest, has been proposed by using multi-objectiye mathematical programming, At the same time, it has been discussed how to determine the whole forest structure of a specific forestry farm which has several tree species to manage. Taking jiang shanjiao Forestry Farm as an example, the whole structure of korean pine, toothed oak and larch is modified and solved. This kind of forest structure has the characteristics of dynamity, entirety, benefits-maximum and inflexity. Meanwhile, it is very easy to be located on the forest land.

Key words: optimal forest structure, multi-objective mathematical programming, Site type, Even-aged forest.