Summary: In this paper, a fractional order financial system is proposed, and the complex dynamical behaviours of such a system are discussed by numerical simulations. We present a method for solving chaos in fractional-order financial system. Also, we derive the Hat function operational matrix of the fractional order integration and use it to solve the fractional-order financial system. To demonstrate the validity of the presented developments, three numerical simulations are given to verify the effectiveness of the proposed method.