||Free convection from a heated oscillating circular cylinder is studied numerically under the conditions of a constant heat flux on the cylinder surface and a constant temperature at far-away. The initial conditions of flow and temperature are those of a free convection flow without the cylinder oscillations. These initial conditions were first obtained mainly with the same procedure as zero oscillations of the cylinder. After that, a sinusoidal oscillation is imposed to cool the cylinder. The velocity field is computed with a two-dimensional laminar flow code, and the temperature distribution is calculated simultaneously by iteration. For numerical convenience, the coordinate is chosen to be fixed with the circular cylinder. Thus the problem is also regarded as the free convection from the heated circular cylinder enhanced by oscillating flows. Various cases of different parameters of Ri number, Re D number, KC number and the directional angle of gravity φ are studied to demonstrate flow patterns and heat transfer characteristics of free convection in oscillating flows. The effects of these parameters are discussed.