Abstract: [Objective] With China becoming the largest country of wood importing and the second largest country of wood consumption in world, the highly dependent on timber imports, has threatened increasingly China's forestry industry security, and China is often accused of the criminal chieftains of "deforestation" and "the black hole" of the world's forest resources. As a big exporter of wooden forest products, there is also a growing risk for serious dependence on the international market. Despite being concerned by many scholars, but at present, there is no unified definition, measuring method and statistical caliber about the foreign trade dependence of China's wooden forest products, and the existing calculation result are very different. All of these have a direct impact on the correct judgment of the degree of dependence on foreign trade of China's wooden forest products, and thus affect the formulation of relevant trade and industrial policies. It is urgent to define the concept and to make a scientific measuring method.[Method] This paper analyzes various definitions, measuring methods, research perspective and purpose, statistical caliber, data sources and existing problems of the dependence on foreign trade in existing researches, and also summarizes the reflected information, the scope of application and the data requirements of different measuring methods. Using the improved measuring method, based on the Chinese forestry statistics, this paper calculates the degrees of the dependence on foreign trade of China's wooden forest products, and makes a longitudinal comparison. Using the data of food and agriculture organization(FAO), this paper calculates and compares the degrees of the dependence on foreign trade of wooden forest products, in major trading countries of wooden forest products.[Result] This paper puts forward a revised value method about the traditional measuring method, which takes into account the industrial structure of the gross output value of forestry industry. Using this revised traditional measuring method, the calculation result show that China's dependence on imports was 12.59% and China's dependence on exports was 14.51% in 2014, all of them were not high. This paper makes clear the application of the log conversion method in the calculation of the import dependence of timber resources supply, proposes the net import dependence of timber consumption and its measuring method, and discusses the problem of recovered paper, defines the log conversion coefficient, the statistical caliber and the data sources in the longitudinal and horizontal comparison. Using the log conversion method, the calculation result show that China's import dependence of timber resources supply were 47.94% and China's net import dependence of timber consumption were 35.85% in 2014, both of them showed the first declining and then rising trend from 2002 to 2014, and were at the medium level compared with the world's major forest products importing countries. The product quantity method should be applied to calculate the production export dependence and the consumption import dependence of certain forest products, this paper illustrates their specific measuring methods. The result of the calculation of China's main woody forest products, show that the production export dependence of these forest products are all below 8%, but it is necessary to pay attention to the export trade security of plywood, especially paper and paperboard, and the consumption import dependences of these forest products are very low, all below 3%, however, the consumption import dependences of particleboard and paper and paperboard were higher, China should further improve their quality and grade to achieve import substitution.[Conclusion] In the calculation of dependence on foreign trade of China's wooden forest products, different measuring methods reflect different information, and have different application scope and different data requirements, so the measuring method should be careful selected, according to the actual research questions and the specific use. On the whole, the dependence on foreign trade of China's wooden forest products was in a relatively security and reasonable range, and they had not formed a real threat to the forestry industry security.

Key words: wooden forest products, dependence on foreign trade, measuring method, measuring and estimating, industry security