A novel model related to triboelectric charging phenomena in toners containing charge control agents (CCA), used as marking materials in copy machines in electrophotography, is proposed. The model was evaluated by comparing the results from computer chemistry using the molecular orbital method (MO), molecular mechanics method (MM), and Monte Carlo method (MC), with the results from measuring triboelectric charge of several toners containing various CCA. The model is based on the interaction of water molecules and CCA molecules. The CCA is divided into two reciprocal polarity regions in the molecule; one region with the same polarity as the CCA charge and another region with the contrary polarity to the CCA charge. The two regions play different roles in CCA toner charging phenomena. Therefore, the polarity and magnitude of the charging is determined from balancing the intensity of interactions among the each region in the CCA molecule and the water molecule. The consequence of molecule structure of CCA to toner charging is elucidated.