Spatial variation of the local capacitance of a lateral p-n(+) junction is measured at various sample biases by our home-made Scanning Capacitance Microscope (SCaM)/Atomic Force Microscope (AFM) which facilitates direct measurements of capacitance itself. Local Capacitance-Voltage (C-V) characteristics are measured at the same time during scanning of the cantilever. it is found that the p-n(+) junction boundary as measured by the SCaM moves toward the p-region at negative bias, and to the opposite direction at positive bias. The local C-V characteristics at around the boundary in the p-region show a low-frequency C-V curve, which in the n(+)-region or just at the boundary, high-frequency C-V curve. These "unusual" phenomena are well interpreted with the help of a device simulator like "VENUS-2D/B".