Several vegetables and fruits, apple, ginger, carrot and pumpkin are dehydrated under various osmotic conditions using sucrose and salt as the permeating agents. The dehydrated materials are then dried. The influence of solute concentration, process temperature and the type of solute on osmotic dehydration and further thermal drying are investigated. The nutrition loss during the osmotic process is measured using carotene as the nutrition index. The effect of calcium chloride present in osmotic solution on the product quality has also been studied. A first order kinetic model is chosen to describe the mass transfer phenomena of the osmotic process. The equilibrium value of water loss, solute gained, kinetic constants KWL and KSG under various conditions are successfully predicted by the model. The relationship between the equilibrium value and four major factors that influence osmotic process of carrot is obtained based on the experimental data. The relations between the loss constant of carotene and the solute concentration in carrot and pumpkin are obtained based on the experimental data. The qualities of dried products are better for the osmotic dehydration pretreated samples than those dried directly.