A three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of banana. The moisture loss, solid gain, weight loss and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Color difference and titratable acidity were decreased by higher concentration. Sweetness was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. The regression models showed a significant lack of fit (p>0.5) and were highly significant with satisfying values of R2. To optimize osmotic dehydration, based on surface response and contour plots, superimposing the individual contour plots for the response variables. the optimum conditions for this process wire 26$^{circ}C$, 44 $^{circ}$brix and 2 hrs for moisture content, sweetness and color difference are less than 72%, 24 obrix and 10 degree.