Recombinant AAV serotype 8 (rAAV8) vector is new and promising for gene delivery，which transduces muscular and hepatic cells highly efficiently. The transduction varies with the administration routes. It was observed that the rAAV8 virus injected intraperitoneally had been delivered to many different tissues through the blood circulation and resulted in extensive and prolonged gene expression. The interest gene (human coagulation factor Ⅸ) has been highly expressed via the rAAV8 vector injected intraperitoneally into mice at the dose of 5×10¹⁰ gc/ mouse. Considerable expression was detected in mouse plasma at two weeks after the administration. Expression peak up to 1 000% level compared to the UCRP occurred between 1～2 months after administration, and then the expression declined gradually but obvious expression persisted at 4 months post administration. APTT test proved the clotting activity of the recombinant hFⅨ in mouse plasma. Immunohistochemical assay showed that the human coagulation factor has been expressed significantly in several organs including liver, kidney, heart and muscles (abdominal and hindleg). These suggest that the rAAV8 virus injected intraperitoneally has been delivered via blood circulation and transduced different cells of multi-organs, and the product of the gene mediated by the rAAV8 vector is biologically active.