The invention discloses a variable gain amplifier with continuously adjustable gain. The variable gain amplifier with continuously adjustable gain comprises an operation transconductance amplifier used for converting an input signal into a current signal; a switching capacitive load connected to the output end of the operation transconductance amplifier and used for converting the current signal output by the operation transconductance amplifier into a voltage signal and amplifying the voltage signal, wherein the amplification time of the voltage signal depends on an equivalent impedance of the switching capacitive load; and an impedance control oscillator used for generating a control clock signal for controlling the size of the equivalent impedance of the switching capacitive load. The control clock signal can be adjusted by an off-chip adjustable resistor which is connected to the impedance control oscillator. A VGA (Variable Gain Amplifier) circuit can realize frequency adjustment of the impedance control oscillator just by using one off-chip adjustable resistor; and a continuous adjusting function for the VGA gain can be realized by using the impedance control oscillator to adjust the switching capacitive load. At the same time, the VGA circuit does not comprise a big resistor and a big capacitor, so that the area of the silicon wafer of the VGA circuit is saved.