The electrical characteristics of light emitting diode (LED) in the re verse-biased state are very important,which can reflect the transport properties of carr iers in the PN junction.In this paper,the capacitance and conductance characteristics of LED samples in the reverse-biased state are studied in experiment and theory.The capacitance and conductance as a function of modulation frequency are obtained experimentally by adding a small alternating current (AC) signal on a direct current (DC) bias voltage.Experimental results show that the capacitance decreases and the conductance increases with the increasing modulati on frequency for reverse-biased LED samples.For LEDs with different I-V characteristics,the reverse-biased capacitance and conductance characteristics are different obviously,even for th e samples with similar I-V characteristics in the forward-biased stat e.This means that the p arameters in the reverse-biased state for LED samples are associated with their properties in th e forward-biased state when working in the normal conditions.Analysis suggests that the reverse -biased capacitance and conductance characteristics mainly result from the tunneling cur rent and surface leakage current.Thus,the reverse-biased capacitance and conductance character istics can be useful parameters to evaluate the performance of light em itting diodes.