Abstract
The investigation round of graphite intercalation compounds (GICs) under high pressure conditions was extended. The intercalant may possess the mono layered or multilayered structures, commensurable or uncommensurable one with graphite matrix. According to this respects we selected such GICs as FeC1, -GICs and ICI-GICs of the first and second stages, C, KHg and sodium-GIC obtained by high pressure technique. The behavior of different GICs under high pressure conditions depends on the properties of intercalated substances in the quasi two dimensional state, thus the elastic properties of carbon matrix can show by different ways