Internal mass transfer during osmotic concentration of apples in sugar solutions was exami-ned as a function of concentration temperature and immersion time of those solutions using moisture loss sugar gain molality and rate parameter. Influence of osmotic concentration processes on browning reaction was also evaluated compared to control In creasin the concen-tration and temperature of sugar solutions increased moistrue loss sugar gain molality and rate parameter. Water loss was rapid early in the process and then levelled off, The same phenomena were occurred on sugar gain only in higher concentration(60$^{circ}$ brix). IN lower concentration (30$^{circ}$brix) sugar gain was gradually increased during whole process. Moisture loss during osmotic concentration using a sugar solution(60$^{circ}$ brix 6$0^{circ}C$) with 180min immer-sion time was 45.79% Effect of osmotic concentration befor air dried to 4% M.C(wet basis) on browning reaction was significant. Minimum browning reaction during air drying was carried out using a pretreatment such as osmotic concentration in sugar solution(60$^{circ}$brix 45$^{circ}C$) with 150min immersion time(O.D=0.01) compared to control(O.D=0.17)