Abstract: The author is one of the members of the Chinese Forestry Delegation to the Ninth world Forestry Congress. After attending this congress, he summarizes his knowledge of the world Forestry in this paper.First of all, he describes the importance of forests. They provide a large amoumt of energy, industrial wood products, food, fodder and other forest products. They protect land and water resources. They are also a vast storehouse of genetic resources. All of these are basic to the well-being, even the very survival of hundreds of millions of people.Secondly, he analyses the challenges to the forests of the world, such as the rapid depletion of forest resources in the tropics and the arid and semi-arid areas, shortage of fuelwood and wood products, damage to forests caused by diseases, parasites, forest fires and environmental pollution and the degradation of forest ecosystem.Finally, he points out the principles and guidelines to the world forestry development and trends of world forestry in the management of forest resources, in the production and productivity of forest industry and also in forestry science, technology and research, forestry education, forestry administrations and forestry policy and legislation.