Triaxial cyclic loading tests up to 20 thousand cycles were performed at confining pressure 19.6 kPa and 49 kPa with axial stress condition under train loads on very compacted well-graded crushed gravel. Before and after the cyclic loading tests, a series of triaxial compression test were performed with unload/reload cycles of axial stress during each monotonic loading. Axial strains were measured accurately on lateral surface of specimen by using local gauges. The stress-strain behavior of very dense gravel was S-shaped. The effect of density on the deformation properties of dense gravel was very large.