The reconstruction of the vegetation development of the Giant Mountains is based on the pollen analysis of mires. The peat profiles studied were taken from the two types of vegetation and topographic diversified complexes; Úpská rašelina Mire (1420 m a.s.l.) is situated in the artic alpine tundra and Černohorská rašelina Bog (1105 m a.s.l.) under the forest limit in the forested zone in a valley of Černá hora Mt. and Světlá hora Mt. Two profiles has been studied from Úpská rašelina Mire, and a profile from Černohorská rašelina Bog. The cores were frozen and subsampled at intervals of 2.5 cm in 1 cm3 subsamples were treated in laboratory by the classic methods of Erdtman and Overbeck (Berglund et Ralska-Jasiewiczowa 1986). The Subboreal has been determined in the submontane zone of Černohorská rašelina Bog. In the submontane zone, mixed forest of Abies and Fagus prevailed. In the montane zone, forests of Picea and Corylus prevailed. In the subalpine zone Pinus (probably, P. mugo) and Betula (cf. B. nana) were important. The Older Subatlantic (2500600 B.P.) was evident from both Černohorská rašelina Bog and Úpská rašelina Mire. Very characteristic is the dominance of Abies and Fagus over Picea. Abies is remarkably dominant tree in this time. Abies and Fagus forest, with Abies prevailing very likely continued both in the submontane zone and in the montane zone. In the Younger Subatlantic (600 B.P. 0) a decline of forest is evident. Pinus and Picea are the most important trees. Picea began to increase again in valleys and depressions. Other trees, especially Abies and Fagus were selectively cut. The Younger Subatlantic is characterized by a general increase of herbs, including anthropogenic indicators and cultivated plants (Secale, Cerealia). Juniperus suggests the existence and expansion of dry pasture and deforestation as well. Picea, Fagus and Abies forests occurred in the submontane zone. Picea forests dominated in the montane zone and Pinus (cf. P. mugo) expanded in the subalpine zone.