The paper deals with simulation of the rotor vibration in a journal bearing. The rotor is maintained in equilibrium during rotation by a fluid pressure wedge created by an oil film. These bearing forces can be modeled as a rotating spring and damper system. The rotor motion is described by complex coordinates of the rotor centerline. The real part of the position vector is a rotor displacement in the X-direction while the imaginary part is a displacement in the perpendicular direction, as we say in the Y-direction. The equation of motion is containing complex variables as a function of time. Equation parameters are complex quantities as well. The paper demonstrates how to solve such an equation using Simuling.