Disclosed are a negative active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same. The negative active material includes a composite particle including a silicon particle and a carbon coating layer coated on the surface of the silicon particle and a porous space formed by the entangled carbon nanofibers, the composite particle contacting the external surface of the carbon nanofibers in the porous space of the carbon nanofiber structure, and the carbon nanofibers have a larger diameter than that of the composite particle and a diameter ranging from about 100 nm to about 2000 nm.