The UNESCO's World Heritage Committee has inscribed the H¹ Long Bay on the World Heritage List according to its outstanding examples representing major stages of Earth's history and its original limestone karstic geomorphologic features. The H¹ Long Bay and its adjacent areas are a part of the Sino-Vietnamese composite terrane, having its development history from pre-Cambrian up to present days. During Phanerozoic, terrigenous, volcanogenic and cherty-carbonate sediments containing in abundance graptolites, brachiopods, fishes, corals, foraminiferas, radiolarias, bivalves, flora, separated one from another by 10 stratigraphic gaps, but the boundary between Devonian and Carboniferous has been considered as continuous. The limestone karstic gemorphology of the bay was developed since Miocene, especially the cone-shaped hills (fengcong), or isolated high limestone karst towers (fenglin) with many remnants of old phreatic caves, old karstic foot caves, marine notch caves form magnificent limestone karst landforms as unique on the world. The Quaternary geology was developed through 5 cycles with the intercalation of continental and marine environments. The present H¹ Long Bay, in fact, appeared after the Middle Holocene maximum transgression, leaving ultimate zone of lateral undercutting in the limestone cliffs bearing many shells of oysters, having the ¹⁴C age as 2280 to > 40,000 y. BP. Geological resources are abundant: anthracite, lignite, oil shale, petroleum, limestone and cement additives, kaolin, silica sand, dolomite, quartzite of exogenous origin, and antimony, mercury of hydrothermal origin. Besides, there still are surface water, groundwater and thermal mineral water on the shore of the H¹ Long - B¸i Tö Long Bays and other environmental resources.