The present invention relates to a negative active material for a lithium secondary battery and a manufacturing method thereof, wherein the negative active material comprises a crystalline or amorphous carbon core, a catalyst layer formed on the core, and carbon vapor growing fiber or carbon nanotubes. The negative active material not only forms a fine path between active materials but also improves conductivity between neighboring active materials so that a battery having improved high rate and cycle life characteristics can be provided, since carbon vapor growing fiber or carbon nanotubes are formed on a surface layer of the negative active material.