A simple method to determine the traps’ density of state(DOS) in organic light-emitting diodes(OLEDs) by manipulating the current-voltage(Ⅰ-Ⅴ) characteristic of the devices at room temperature is introduced.In particular,the trap-dependent space-charge limited current formula is simplified to obtain effective density of traps.In this study,poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)](F8BT) and 2-Methoxy-5-(3’,7’-dimethyloctyloxy) benzene-1,4-diacetonitrile(OC_1C_(10)-PPV) are selected as the OLEDs emissive layer.The trap DOS of F8BT- and OC_1C_(10)-PPV-based OLEDs are calculated in the magnitudes of 10~(24)m~(-3)and 10~(23)m~(-3),respectively.In addition,the results agree with the other conventional method which is used to determine the trap DOS in OLEDs.This calculation technique may serve as a robust and reliable approach to obtain the trap DOS in OLEDs at room temperature. A simple method to determine the traps’ density of state (DOS) in organic light-emitting diodes (OLEDs) by manipulating the current-voltage (I-V) characteristic of the devices at room temperature is introduced. dependent space-charge limited current formula is simplified to obtain effective density of traps.In this study, poly [(9,9-di-n-octylfluorenyl-2,7-diyl) -alt- ] thiadiazol-4,8-diyl] (F8BT) and 2-Methoxy-5- (3 ’, 7’-dimethyloctyloxy) benzene- 1,4- diacetonitrile (OC_1C_ (10) -PPV) are selected as the OLEDs emissive layer. The trap DOS of F8BT- and OC_1C_ (10) -PPV-based OLEDs are calculated in the magnitudes of 10 ~ (24) m -3 and 10 ~ (23) m -3, respectively. In addition, the results agree with the other conventional method which is used to determine the trap DOS in OLEDs .This calculation technique may serve as a robust and reliable approach to obtain the trap DOS in OLEDs at room temperature.