Abstract: Based on a class of parameter-adjustable chaotic systems, an improved four-dimensional memristive chaotic system is established by replacing the gain resistor of the original system circuit with a memristor. Theoretical analysis demonstrates that the new system possesses two line equilibrium points and can generate self-excited attractors. The dynamics of the new system are analyzed through numerical simulation such as bifurcation diagrams, Lyapunov exponents, phase diagrams, etc. With the variation of initial conditions, the memristive system with fixed parameters exhibits not only the extreme multistability phenomenon of coexisting infinitely many attractors but also complex transient behaviors. Finally, to validate the theoretical and numerical simulation results, an equivalent circuit of the memristive chaotic system is designed, and hardware circuit experiments as well as PSIM circuit simulations confirm the correctness of the MATLAB numerical simulations.