Extinction characteristics of tubular flames diluted with nitrogen in a rotating flow field have been experimentally investigated. The extinction limit was mapped as functions of the equivalence ratio φ and the added nitrogen ratio χ , and the flame diameter and temperature at extinction limits, the flame structure and the stable species concentration in the tubular flame near the extinction limits have been measured. Results show that, as compared with other results for the usual propagating flames in a tube or the flat, twin flames, the flammable range shifts towards the fuel-lean side for methane and towards the fuel-rich side for propane; among others, the lean limit of methane becomes minimum and the rich limit of propane becomes maximum; the maximum allowable dilution by nitrogen occurs at the lowest equivalence ratio for methane flames ( φ =0.87) and at the highest equivalence ratio for propane flames ( φ =1.75). This shift is more remarkable than that obtained by the tubular flame in nonrotating flow field. Measurements on the concentrations of the product and intermediate species in the inner core have also shown that these values are shifted towards the fuel-lean side in methane flames and the fuel-rich side in propane flames. From these results, it seems that although the characteristics of the tubular flame in the rotating flow field are influenced by the stratification through preferential diffusion and the Lewis number through stretch as those of the other stretched flames, this effect is promoted by its curvature and the rotating motion of the mixture.