Aim: Stem cells hold great promise for brain and spinal cord injuries (SCI), but cell survival following transplantation to adult central nervous system has been poor. Salvianolic acid B (Sal B) has been shown to improve functional recovery in brain-injured rats. The present study was designed to determine whether Sal B could improve transplanted mesenchymal stem cell (MSC) survival in SCI rats. Methods: SCI rats were treated with Sal B. The Basso-Beatie-Bresnahan (BBB) scale was used to test the functional recovery. Sal B was used to protect MSC from being damaged by TNF-α in vitro. Bromodeoxyuridine-labeled MSC were transplanted into SCI rats with Sal B intraperitoneal injection, simul-taneously. MSC were examined, and the functional recovery of the SCI rats was tested. Results: Sal B treatment significantly reduced the lesion area from 0.26±0.05 mm2 to 0.15±0.03 mm2 (P<0.01) and remarkably raised the BBB scores on d 28, post-injury, from 7.3±0.9 to 10.5±1.3 (P<0.05), compared with the phosphate-buffered saline (PBS) control group. MSC were protected from the damage of TNF-α by Sal B. The number of surviving MSC in the MSC plus Sal B groups were 1143.3± 195.6 and 764.0±81.3 on d 7 and 28, post-transplantation, more than those in the MSC group, which was 569.3±72.3 and 237.0±61.3, respectively (P<0.05). Rats with MSC trans-planted and Sal B injected obtained higher BBB scores than those with MSC transplanted alone (P<0.05) and PBS (P<0.01). Conclusion: Sal B provides neuroprotection to SCI and promotes the survival of MSC in vitro and after cell transplantation to the injured spinal cord in vivo.