An electrode includes an electrode active material, wherein the electrode active material layer includes an electrode active material, polyvinylidene fluoride, and a conductive agent, wherein the conductive agent includes a carbon nanotube structure in which 2 to 5,000 single-walled carbon nanotube units are bonded to each other, and the carbon nanotube structure is included in an amount of 0.01 wt % to 0.5 wt % in the electrode active material layer. A secondary battery including the same, and a method of preparing the electrode are also provided.