A method for improving circuit stability is disclosed. In the method of the present invention, the circuit is analyzed to find the frequency band in which the input impedance at a target node behaves as a negative resistance, and then find the signal path of the frequency band in the matching circuit in front of the target node and add an attenuator in the signal path. This prevents the circuit from oscillation and improves the stability of the circuit. Furthermore, the signal on the main signal path will not be attenuated and the performance of the circuit will be maintained.