Abstract: Chua＇s circuit is the simplest circuit, which can become chaotic. The circuit exhibit rich of dynamic phenomenon, it contairis three energy storage elements only. We illustrate the chaotic of the circuit by observe period 1, period 2, single scroll and double scroll chaos attractors, we obtain the chaotic signal by adjusting the parameters of the circuit . Meanwhile we show how to use computer simulate the conclusion of complex dynamic phenomena. We analyze the frequency spectrum with FFT method and simulate the nonlinear equations by using Runge - Kutta method, We also do the curve fitting with least square method. This approach could be use for reference in university experimental study on Chua＇s circuit.

Key words: chaos, Chua＇s circuit, phase portrait, least square method, FFT, Runge - Kutta method