The present method is related to a molecular press dehydration method of vegetative tissues using water-soluble polymers in solid-phase as dehydrating agents. The molecular press dehydration method of the present invention is characterized by that dehydration is done by induction of cytorrhysis to vegetative tissues mixed with water-soluble polymers such as PEG, gum arabic, arabinogalactan, egg albumin, milk protein, soybean protein, etc. in its solid-phase. Compared to the conventional dehydration methods, the present method enables to obtain much greater dehydration effects in the amount and the rate, even though a very small amount of polymer substance is used; and the method enables to obtain excellent quality of dehydrated tissues as well as dehydrated exudates; and is environmentally friendly under favor of reduced energy consumption. The dehydrated vegetative tissues are excellent in their storage stability, and flavor and texture after rehydration, and dehydrated exudates are excellent in the concentrated useful components, flavor, and preservation quality. Therefore, the dehydrated vegetative tissues and exudates obtained by using the dehydration method of the present invention may be usefully applied to various fields such as foods and beverages, feeds, cosmetics, medicines, flavorings, agricultural chemicals, coloring agents, etc. according to the characteristics of plants.