The effect of feeding silkworm larvae (chines hybrid) on mulberry leaves (Balady variety) stored under room and cooling (refrigerator) condition for 1,2 and 3 days, beside fresh (control) mulberry leaves on some biological and productivity characters were studied. (A) Biological studies:                 Larval duration period values and percentage of mortality of larval stage tended to increase with increasing storage period of mulberry  leaves under room or cooling conditions. The lowest values were recorded for larvae fed on fresh mulberry leaves (control). On the other hand, the cocooning percentage was not affected by such treatments; while, pupation percentage reached to its maximum (97.23%) and to the minimum (85.87%) in larvae fed on mulberry leaves stored under room temperature for one and three days, respectively.                 Pupal period of male  and female  and pupal weight  significantly  increased in larvae fed  on fresh leaves than those larvae fed on storage leaves under room and cooling conditions, respectively.                 Adult emergency percentage, longevity of male and female fertility (%) were not affected with fresh or stored mulberry leaves. However, female longevity, fecundity and hatchability percentage were increased significantly (in most cases) by storing mulberry leaves. (B) Morphometerical studies:                 Weight (g.) of full grown larvae and body weight of pupae (g.), in addition to length and weight of silkgland (g.) were significantly increased when larvae fed on fresh mulberry leaves than those fed on stored ones. (C) Technological studies:                 Determined technological parameters such as mean weight of fresh cocoon (g.) and mean weight of cocoon shell (g.) significantly increased also in larvae fed on fresh mulberry leaves than those fed on stored mulberry ones.