Abstract: The conductance control theory wasused to investigate and analyze the properties of mini-structure γ-Fe₂ O₃ adding with Y or SO₄^2-,such as heatstability,sensitivity to benzene hydrocarbon gases and high selectivity to simila r gases.DTA,TEM and RQ-1instrument were used to characterize the properties of γ-Fe₂ O₃ material.The resultsuggest appropriate doping of Y₂ O₃ can make the phase change temperature of γ-Fe₂ O₃ up to 618℃,which can improve the thermal stability of γ-Fe₂ O₃ based sensitive elements.Appropriate doping of SO₄^2- and Au⁺ can contribute to improve the sensit ive properties to benzene hydrocarbon g ases.Ultrafine γ-Fe₂ O₃ based materials reinforce the surfa ce sensitive mechanism.So anew approa ch is obtained to develop sensitive e lements response to benzene hydrocarbon gases.