The change of dielectric properties on Fuji apples with red-dot disease stored at constant temperature was investigated, which provides a new theoretical basis for revealing its pathogenetic mechanism at electrical properties. By applying LCR electronic measure instrument, the fruits’ dielectric properties, which include the impedance, reactance and inductance, were determined at 100 Hz, 1, 10, 100 kHz and 1 MHz at 20℃. The results indicated that the dielectric constant, impedance, reactance and inductance for all fruits decrease with the increase of frequency at the same stored days. Moreover, there was a significantly positive correlation among impedance、reactance and inductance, the value of the loss tangent and dielectric constant is significantly different (P<0.05), but the value of the impedance, reactance and inductance is not significantly different (P＞0.05) between the diseased and normal fruits from 100?Hz to 1 MHz. This research revealed that the loss tangent and dielectric constant could reflect the quality of apples in some extent. 