Acute pancreatitis (AP) is a common acute abdominal disease, 10%-20% of which can evolve into severe acute pancreatitis (SAP). SAP causes significant morbidity and mortality. RhoA/Rho kinase is activated in SAP. Bone marrow-derived mesenchymal stem cells (BMSCs) have been demonstrated to be a therapeutic role in SAP, but the underlying molecular mechanism is still unclear. This study was designed to determine whether RhoA/Rho kinase involved in APS, and the specific mechanism of BMSCs in APS. We validated that BMSCs could promote renal repair, reduce the ratio of wet to dry kidney weight, renal EB concentration, pancreatic edema and serum amylase, Cr, BUN and systemic TNF-alpha, IL-6 levels. BMSCs also reduce ROCK I and increase ZO-1 protein levels in APS, but the effects are inhibited by RhoA/Rho promoter CNF1. These results indicated that BMSCs can alleviate SAP rat kidney injury by inhibiting the RhoA/Rho kinase signaling pathways, increase the ZO-1 expression, reduce capillary permeability, blood capillary leakage and improve renal function.