Irradiation induces bone injury by generating free radicals that adversely affect the microenvironment for Mesenchymal stem cells (MSCs) and damages bone marrow blood vessels. We wished to investigate the efficacy of antioxidant administration in protecting stem cell microenvironments and promoting bone marrow vasculature recovery after radiation treatment. The antioxidant ascorbic acid was administered 3 times at a dosage: 150 mg/kg/day to experimenttal groups 3 days before targeted radiation by a unique Small Animal Radiation Research Platform (SARRP). Histological staining indicated that antioxidant treated mice had less severe bone marrow damage 1 week after irradiation with substantial marrow cellular recovery 4 weeks later. Flow cytometry analysis showed that antioxidant administration was correlated with a rebound in MSC quantity in bone marrow. Anti-oxidant treatment was also observed to allow for better vasculature retention and recovery through angiographic imaging. Our data suggests that pre-treatment with ascorbic acid serves to improve bone marrow microenvironments for bone marrow stem cells after radiation treatment.