Research results show that nitrogen assisted SAGD exploration technology has the feasibility to be used in Guantao oil reservoir of Du 84 block; it can promote steam chamber in sideways to increase available reserves and can extend SAGD production time and increase oil steam ratio and reservoir recovery factor. Keywords: GAS-SAGD, Physical simulation, Numerical simulation, Steam override, Thermal efficiency Foreword Steam Assisted Gravity Drainage (SAGD) is a kind of economic and effective technology in developing Super-heavy oil reservoirs. However, due to the variety and complexity of the oil reservoirs, a lot of problems appear during the implementation of SAGD. As a result, researches on corresponding improved SAGD technology in accordance with the features of oil reservoirs, are urgent for current complex features and development conditions. After specific literature search on improving oil recovery at home and abroad, the author puts forward a technology of GAS-SAGD, and makes a feasibility study on this technology by the means of high temperature and high pressure two-dimension physical simulation and numerical simulation, with the example of Guantao oil reservoir of Du 84 block in Liaohe oilfield, and optimizing injectionproduction parameters for the field implementation.