  We take advantage of the red clump stars to build the relation of the optical
extinction (AV) and distance in each direction of supernova remnants (SNRs)
with known extinction in the fourth Galactic quadrant. The distances of 9 SNRs
are well determined by this method. Their uncertainties range from 10% to 30%,
which is significantly improved for 8 SNRs, G279.0+1.1, G284.3-1.8, G296.1-0.5,
G299.2-2.9, G308.4-1.4, G309.2-0.6, G309.8- 2.6, G332.4-0.4. In addition, SNR
G284.3-1.8 with the new distance of 5.5 kpc is not likely associated with the
PSR J1016-5857 at 3 kpc.
