Abstract: The article, by using system an alysis, presents the characteristics of timeliness and space, continuity, servce, controllment and economy of tree length flow in forest harvesting system. To minimize the production cost and storage cost of tree length flow and balance the tree length transportation and operation in log yard as the objective, the macrocontrol and microcontrol mathematical models of tree length flow are developed. The practical examples show that the economic results of “two-step hauling”are more significant than that of “hauling in summen and storage in winter (flow)”.

Key words: Tree length flow, Macrocontrol, Microcontrol, Balance production, Economie resalts