The codimension-2 bifurcation in a three-dimensional differential system derived from the famous Chen system was investigated.At first, the equilibrium discussed in the original system was translated to the origin of the coordinates of the new dynamical system by the change of variables.Then the parameter conditions for the codimension-2 Bautin bifurcation were presented by analyzing the Jacobian matrix of the corresponding system.Bifurcation diagrams of the aforementioned system, which demonstrate the Bautin bifurcation, were obtained by numerical simulations.It is shown that the numerical results agree very well with the analytical ones, thus validating the theoretical analysis.