A negative electrode material capable of absorbing and desorbing lithium is comprised of a mixture of coke and graphite. The amount of graphite in the mixture is near to that which induces percolation transition. Preferably, the amount of graphite in the mixture is 2 to 37 wt % relative to the total amount of the coke and graphite. The coke may be prepared by heating raw coke from oil or coal at 500 to 900.degree. C. The coke may be 0.06 or more in the atomic ratio of hydrogen to carbon and 0.003 or more in the atomic ratio of oxygen to carbon. The graphite may be 0.5 .mu.m to 30 .mu.m in a mean particle size. Lithium secondary batteries comprising the negative electrodes have a large discharge capacity.