BACKGROUND: Infusion of mesenchymal stem cells (MSCs) via portal vein is one of the main ways for MSCs transplantation to treat liver cirrhosis (LC). As the tissue of LC showed diffuse fibrosis and thickened Glission sheath, the soft pig-tail catheter, or central venous catheter can not successfully insert the portal vein. Thus, our study used an improved method and performed a relatively comprehensive system to evaluate the effect for human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) transplantation. METHOD: Fifteen patients with hepatitis B-related cirrhosis were enrolled in the study, and we performed hUC-MSCs transplantation via portal vein by using an 16-G needle and 0.035-inch guide wire combined with 7FR "retentional metal stiffner trocar" of pig-tail catheter under the guidance of contrast-enhanced ultrasound. Serum liver function, fibrotic indicators, tissue stiffness, coagulation function, and hemodynamics were measured at weeks 4, 12, and 24 after MSCs transplantation. Liver biopsy was performed before and 24 weeks after hUC-MSCs transplantation. RESULT: After hUC-MSCs transplantation, the prothrombin time was lower than before. The levels of hyaluronic acid and IV-C(Type IV collagen) in fibrotic indicators were significantly reduced, and the Young's modulus was also decreased. Moreover, liver biopsy showed that the lytic necrosis of hepatocyte was decreased. In liver hemodynamics, the portal vein diameter was decreased after hUC-MSCs transplantation. CONCLUSION: hUC-MSCs transplantation can alleviate liver damage caused by LC. The improved "retentional metal stiffner trocar" of pig-tail catheter was safe and effective in the infusion of hUC-MSCs transplantation, which is worth promoting in clinical practice.