Abstract: Polyaniline/Sulfur composite was synthesized by the in-situ polymerization,when aniline was polymerized through chemical oxidative polymerization with the presence of sulfur.The material was characterized by using scanning electron microscopy.The results show that aniline is preferentially polymerized on the surface of sulfur to form a layer of polyaniline on the sulfur surface.Electrochemical characterizations were carried out by using constant charge/discharge,cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that the polyaniline/sulfur composite exhibits excellent electrochemical properties,when the charge-discharge current density is 0.2 mA/cm²,the initial capacity of the composite is as high as 1134.01mAh/g and the specific capacity is 526.89 mAh/g after 30 cycles.EIS results show that PANI can reduce the electrochemical reaction resistant.