We have recently reported the development of a high efficiency expression vector, pCK, which can drive a high level of gene expression in mouse skeletal muscle. In this study, we tested the therapeutic potential of pCK expressing human VEGF165, pCK-VEGF in the rabbit ischemic hind limb model. To determine the optimal dose of plasmid DNA, various concentrations of pCK-CAT were injected into the muscle of a rabbit hind limb and the levels of CAT activity were determined. It was found that the expression level of the exogenously added gene became stable between 250 and 1,000 $mu$g. Based on this result, we tested whether intramuscular transfer of 500$mu$g of pCK-VEGF could actually modulate collateral vessel development in a rabbit ischemic hind limb model. It was found that relative to the control group injected with the pCK lacking the VEGF sequence, single intramuscular doses (500$mu$g) of pCK-VEGF produced statistically significant augmentation of collateral vessels as determined by the angiographic vessel count, maximal blood flow by Doppler flowmeter and the number of capillaries by histology. These results suggest that a single 500$mu$g-delivery of pCK-VEGF is potent enough to induce sufficient angiogenic activity and achieve therapeutic benefit on this rabbit model.