Conversion of green house CO 2 into fuel gas in the presence of reducing agent sources that are Fe and Zn powder, as well as hydrogen ions supplier such as nitric and acetic acids by photo catalytic reduction with water vapor on TiO 2 has been studied.The photo reduction was carried out by batch technique, using a UV lamp with a wave length of 290-400 nm, as a photon source.The gasses produced from the photo reduction were determined by gas chromatography.The research results indicate that the photo reduction of CO 2 has successfully produced methane as a dominant product.The presence of the metals in addition to be able to improve the methane yield, it is also able to induce ethylene formation.Meanwhile the acids can considerably enhance the methane yield without formation of ethylene.Furthermore, the enhancement is observed to be controlled by mass of the metals, and the acid concentrations.It is also found that Zn and HNO 3 show stronger effect in the increasing CO 2 photo reduction.