The article deals with the problems of state-society relations in Russia during the First World War (1914 - February 1917) in the context of nationwide mobilization processes. The term “nationwide mobilization” is used in a broader sense which means engagement of the belligerent nation in the governmental war efforts. The author discusses the ways of spiritual mobilization of the Russian nation by means of patriotic propaganda, rituals, symbolic actions and civil activity. The author describes the powerful upsurge of patriotic sentiments sweeping across all regions and social social classes at the beginning of the War; characterizes general moods and their evolution as well as specifics of different social groups' attitudes toward the War; shows the forms of state-society collaboration and civil activity, practices of social self-organization of the population under wartime conditions in the context of relations between the government and the society. The article evaluates activities of the All-Russian Zemstvo Union, All-Russian Union of Towns, War-Industrial Committees and other organizations engaged in mobilization of the rear areas and solving social problems of combatants and civilian population. The author stresses the significance of the Russian army's defeats in the spring and summer of 1915, the “great retreat”, which vividly demonstrated the enormous oversights in the country's preparations for war, organization of the army's supply with weapons, ammunition, and clothing, as well as consequences of insufficient coordination and incompetence of the military and civilian authorities. The role of political crisis, confrontation between the authorities and society which had grown since the middle of 1915, the mutual power-society distrust in the outlet of national mobilization project is discussed. The article reveals several factors of the evolution of state-society relations which determined the general crisis of national mobilization process.