A possible refinery process with higher output of gas oil and more hydrogen consumption than in conventional refinery processes was proposed. The CO, emissions form the proposed processes with (case B) and without (base case, A) outer source of hydrogen were evaluated. The possibility of combining the refinement and transportation of petroleum with hydrogen produced from renewable energy resources such as hydropower and solar cells (photovoltaic, PV) was discussed by life cycle assessment (LCA), where hydrogen is supplied to the refinery process installed overseas and the lighten and desulfurized products are transported to Japan (case Q. The result was compared with the case when liquefied hydrogen is transported to Japan and supplied to a refinery installed in Japan (case B). CO2 emissions from the proposed refinery processes with (case B) and without (case A) outer source of hydrogen were calculated with 159 and 141 kg-CO2/kl-produced oil, respectively. In any case with outer hydrogen supply (cases B and Q, the total CO2 emission was less than that for case A, when the hydrogen is produced from hydroelectricity. On the other hand, when the hydrogen is produced from PV, total CO2 emissions for cases B and C were larger than that for case A. Finally, the characteristics of case C was identified and the conditions for the product import case (case Q can show the best one with the minimum CO2 emission were discussed.