There are extensive evidences that degeneration process after spinal cord injury could be a good reason for nervous system (peripheral and/or central) problems. In this study the effects of cell administration on Alpha motoneurons regeneration after Spinal Cord Injury (SCI) in rat was investigated. Twenty four male Wistar rats divided to 3 groups (control, Spinal Cord Injury (SCI), (SCI) + stem cell administration n = 8). After 4 weeks the lumber segments of spinal cord were sample, processed, sectioned serially and stained with toluidine blue (pH = 4.65). By using sterological quantitative technique (physical dissector), the number of alpha motoneurons in the right ventral horns of spinal cord were counted and compared with each other. Statistical analysis showed treatment with stem cell at four week significantly (p<0.05) reduced neuronal damage and progress the regeneration. The numerical density in this group is near to control group. Then it is consulted that cell administration could reduce the degeneration rate of Alpha motoneurons after Spinal Cord Injury (SCI) in rat.