Introduction. An important condition for the successful implementation of the Russian Federation strategic development goal ‒ an increase in the population life quality based on sustainable economic growth ‒ is an increase in investment activity, which forms the basis of the post-industrial technological structure. The difficulties of adapting forestry and the forest industry to market conditions, challenges of economic development current stage have actualized the issues of detecting increasing investment activity factors in the forest complex, determining its investment security. Purpose. The purpose of the research is to identify destructive factors that generate threats and risks to the forest complex sustainable development and forming activating investment processes mechanisms as a condition for achieving investment security. Materials and methods. The methodological basis of research is systems approach provisions. The research is based on the principles of objectivity, coherence, synergy. The object of research is investment processes in the forest complex, the subject of research is the factors and mechanisms for increasing forest complex economic agents investment activity. When conducting the research, the method of qualitative and quantitative content analysis, abstract-logical, monographic, comparative methods were used. Research results, discussion. The article summarizes and systematizes, in relation to the forest complex, the diverse theoretical, methodological and applied research conducted within the problems of investment security framework as a typological type of economic security. The features of development and investment activity in various areas of the forest complex are analyzed, which allowed us to form key investment directions and components of the mechanism for activating investment processes in the forest complex to ensure its investment security. Particular attention is paid to the role of the state in addressing issues of financing investments and investor support. Conclusion. The proposed mechanisms and tools for increasing investment activity in the forest complex are aimed at achieving its sustainable development while preserving the potential of forests, which corresponds to the goals of the federal project “Forest Conservation” of the national project “Ecology” and the Strategy for the Development of the Forest Complex of The Russian Federation.