Abstract: The paper set forth the concepts and goals of forest ecosystem management, the status and function of the tending thinning-improvement in running through the process of forest ecosystem management. And the conclusion had been brought forward that the syncretizing of thinning and harvesting as well as the combining of tending and alteration are the practice trend of forest ecosystem management. In China, it is being in the process of enforcing conservation project of natural forest and trying to settle the soil degredation problem of plantations. It is very important to tend thinning-improvement of stands.Through analysis of the practice samples from domestic and overseas, the author considers that the sustainable development of forestry lies in the sustainable mounting up of forest resources. And in turn, the sustainable mounting up of forest resources lies in the scientific management of stands. The forest ecosystem management is the optimal choice of forest management pattern in the 21st century, and the tending thinning-improvement of stands is the sticking point of the forest ecosystem management.