  We present a study of a young (few years old) supernova remnant 2003lx which
was first discovered in X-ray through two serendipitous Swift observations in
2008 January and the corresponding merged image revealed a 7\sigma source
detection at $2.1\pm1.2$ arcsec (0.9 +/- 0.5 Swift pixels) from the optical
position of the supernova. The X-ray luminosity $L_x = 4.8_{-1.7}^{+1.8} \times
10^{41} erg/s of band 0.3 - 2.0 keV is estimated by a redshift z = 0.0377 power
law which can infer a companion star with a mass-loss rate of \dot{M} ~ 10^{-4}
M_\sun per year (with assumption of wind velocity v_w = 10 km/s) in the white
dwarf binary system. Thermal Model fitting suggests the temperature of the
shock wave front is kT ~ 0.4 keV which is consistent with the typical reverse
shock temperate. The X-ray emission allows us to probe the interaction between
the fast moving debris of the exploded star and the circumstellar medium (CSM).
This in turns provides footprints of the mass-loss history of the exploded
system, and may allow us to learn about the nature of the progenitor and its
companion.
