The author addresses the fabrication method and the Ragon plot measurement of lithium ion capacitor for basic characterization. The preparation of activated carbon electrode as positive electrode is the same as that for electric double layer capacitor. The Ragon plot can be obtained by the constant power mode using the two-electrode cell composed of activated carbon electrode (positive electrode) and Li+-doped graphite electrode (negative electrode). It is useful for laboratory-scale basic characterization to pre-dope Li+ ion to the graphite electrode using a different other two-electrode cell from that for the Ragon plot measurement.