This research was carried out at (D.S.C) in beet campaign of (2017) to study the effect of cooling rate and retention time of masscuites  in sugar losses in beet molasses. Beet roots and final molasses  under studied were taken from the Factory. All samples of molasses were analyzed for the following:(total soluble solids TSS), sucrose, purity, non-sucrose, raffinose, reducing sugar and dextran. Also measured the specific gravity, color % brix and pH. The obtained results illustrated the following conclusions:The quality of sugar beet root was good value 82.23% ,(total soluble solids TSS), in molasses ranged from79.70% to 79.8%, sucrose 48.32 to 48.77%, raffinose 1.41% to 1.71%, reducing sugar 0.35% to0.73%, dextran 0.25% to 0.46%, normal specific gravity with average of 1.415%, color % brix ranged from  30231.30 to 35765.70 and pH8.8 to pH9.3 in both production lines (1) and (2) respectively; Very low values of non-sugar to water ratio ( NS/W) with average of  1.57% and 1.51% in the two production lines (1) and (2) respectively. Decrease the sugar losses in final molasses to good values by increasing the quantity of cooling water and retention time  inside the vertical cooling crystallizer for C- masscuites in both production line (1) and (2)  in Delta Sugar Company.