The invention relates to a variable resistance characteristic demonstrator, in particular to variable characteristic demonstrators of a thermal resistance, a photoresistor, a piezoresistor, a hygristor and a magneto resistor. The circuit comprises an Ohmmeter, a change-over switch, the thermal resistance, the photoresistor, the piezoresistor, the hygristor, the magneto resistor, a 555 integrated circuit, a resistor, a capacitor and a light emitting diode; the variable resistance characteristic demonstrator is characterized in that one end of the thermal resistance, the photoresistor, the piezoresistor, the hygristor, the the magneto resistor and the Ohmmeter is connected with the positive electrode of a DC power supply after parallel connection, while the other end thereof is connected with a pin 2 and a pin 6 of the 555 integrated circuit through the change-over switch and the resistance, one end of the variable resistance is connected with the change-over switch, while the other end thereof is connected with the negative electrode of the DC power supply. By adopting the technical proposal, the variable resistance characteristic demonstrator has the advantages and active effects that the variable characteristics of the thermal resistance, the photoresistor, the piezoresistor, the hygristor and the magneto resistor can be demonstrated through the reading changes of the Ohmmeter and the working state of the light emitting diode with high visualization and low cost.