Provided are an MIT device-based oscillation circuit including a power source, an MIT device and a variable resistor, in which a generation of an oscillation and an oscillation frequency are determined according to a voltage applied from the power source and a resistance of the variable resistor, and a method of adjusting the oscillation frequency of the oscillation circuit. The MIT device includes an MIT thin film and an electrode thin film connected to the MIT thin film, and generates a discontinuous MIT at an MIT generation voltage, the variable resistor is connected in series to the MIT device, and the power source applies a voltage or an electric current to the MIT device. The generation of an oscillation and an oscillation frequency are determined according to the voltage applied from the power source and the resistance of the variable resistor.