Composite electrode material of crystalline b-FeOOH and carbon was prepared by hydrolyzing of FeCl3 (aq.) in which carbon powder with various specific surface areas was dispersed. Composite electrode material of b-FeOOH fine particles and Ketjen black (KB:specific surface area 1270 m2 g-1) of high specific surface area exhibited the high capacity over 250 mAh g-1 per b-FeOOH weight and good cycle performances at rapid charge-discharge current density over 5 mA cm-2 (ca. 5.0 A g-1 per b-FeOOH weight) in nonaqueous electrolytes including lithium ions. Composite electrode materials of crystalline b-FeOOH and carbon are one of the promising candidates as electrode materials for energy storage devices that high-power operations are required.