Well-graphitized coke powder was further heat-treated at 2200degreesC with various amounts of boron in Ar to prepare coke powders containing different amounts of dissolved boron. The particle size distribution, specific surface area, crystallite size, and the texture observed with transmission electron microscopy were less dependent on the concentration of residue boron, [B](res), after the heat-treatment. The dissolved boron concentration, [B](sol), was quantitatively estimated from the potential curve of the first lithium doping. [B](sol) was equal to [B](res) when [B](res) less than or equal to1.0 wt % and slightly decreases with the increase of [B](res) when [B](res) greater than or equal to1.0 wt %. The irreversible capacity of the first lithium dope-undope cycle monotonously decreased, became minimum at about 0.4-0.5 wt % [B](sol), and again slightly increased with the increase of [B](sol). The discharge capacity of the first cycle was monotonously raised with the increase of [B](sol). The mechanisms of irreversible capacity and discharge capacity depending on [B](sol) are discussed.