Solar, oven and open-direct sun drying experiments in thin-layers of mango slices were conducted at the Department of Food Processing Engineering, Faculty of Engineering and Technical Studies, University of El Imam El Mahdi, Rabak, White Nile State Sudan. The objectives of the study, is to compare between different drying methods of mango, these methods are oven, solar, and open-direct sun drying, Some drying characteristics were used for comparison and evaluation, these are drying time  and drying rate. Chemical compositions for fresh and dry mango were done. The change in mass of mango slices were recorded continuously every one hour interval. The results indicated that Fresh sample of mango had (78.77, 1.40, 0.32, 0.55, 9.96 and 9.00) % of moisture, protein, ash, fat, fibers and carbohydrates (on dry wet Basis) respectively. Also results showed that, mango slices were dried from an initial moisture content of 78.8 % (w.b.) for all drying methods to the final moisture content of 0% (w.b.) in 24 hours for oven drying method, while The final moisture content of 22.3% (w.b) in solar drying method with drying time of 18 hours, the final moisture content of 46.7%(w.b.) for open-direct sun drying method with drying time of 16 hours. The drying process occurs in the falling rate period for all the drying methods and more change in moisture occurs in the first day of drying. The drying rate for oven, solar and open-direct sun were found to be (0.78, 0.16 and 0.16)% respectively. Quality analysis of (Moisture content, oil content, ash content, crude fiber, protein content and ‎carbohydrate content) for fresh and dried mango revealed that drying reduce the moisture content and increase the dry matter of mango slices and consequently improved their quality.