The interaction of a single vortex ring with non-premixed flame was experimentally studied. A single vortex ring of gaseous fuel generated through a round nozzle was ignited by the residual flame sustained at the nozzle tip after fuel shut-off and visualized to study the phenomena occurring at various conditions by Schlieren and scattering techniques. Production of initial circulation of a non-reacting vortex ring was measured to clearly define the initial conditions. The boundaries of regime of the flame extinction, which occurs due to the excessive strain at the stagnation point, were mapped by the initial conditions. Tip propagating velocity and lateral width of the reacting or non-reacting cases were measured to see the dependency of the behavior of vortex rings on the governing parameters and the buoyancy effects on the vortex rings. Buoyancy increased the circulation of a vortex in upward case, while decreased in downward case. Temperature signal taken from thermocouple showed the slow entrainment to the core region of vortex ring flame. Flame roll-up seemed not to occur in this combustion field, different from other studies of numerical analysis.