With the changing global security situation, increase in external threats or emergence of new ones (cyberattacks, onconventional warfare models, etc.), countries must feel concern regarding consolidation of their security (e.g. Novikovas et al. 2017; Šišulák 2017). The fight against terrorism and the mitigation of climate change are key challenges facing global social changing. The issue of climate change is in synergy with the concepts of ecological, economic and energy security. Global development increasing demand of energy, triggered by increasing population and respective increase of economic activities, and consequent environmental degradation (Tvaronavičienė, 2016). Climate change and increasing human activities posing a serious threat to the ecological security in different fields (Li et al. 2017). Terrorist attacks in the USA, floods in 2002, shaped new attention EU Institution to Critical Infrastructure (CI) concept, as an element of security. Critical infrastructure, as a phenomenon (for example energy), has become an argument in making political decisions (Tvaronavičienė, 2012). One of the ecological security elements is municipal waste management, which, as a business sector, is characterized as a complex phenomenon, which includes: infrastructure-engineering, administrative-functional, political and technological aspects. The aim of the topic is to analyze the municipal waste management sector as a phenomenon of national security. The topic reveals theoretical insights of the municipal waste management sector, identified it as a critical infrastructure object, in the context of Lithuanian national security. The object - peculiarities of legal regulation of critical infrastructure in EU and Lithuanian legal acts. The authors applied scientific methods such as document analysis, teleological, critical-analysis, comparative and generalization.