Supernova remnants are an excellent laboratory to study many fundamental subjects of modern
astronomy and astrophysics such as the nature of stellar evolution, explosion, interstellar chemical
evolution, and cosmic-ray acceleration. With the emergence of modern X-ray observatories supernova
remnant study has been revolutionized for the last decade. We briefly introduce recent results from
deep X-ray observations of Type Ia supernova remnants, Kepler and G299.2-2.9. We detect Fe-peak
ejecta elements Mn, Cr, Fe, and Ni in Kepler. Our estimated mass ratios among these elements show
that Kepler's supernova was a thermonuclear explosion of a relatively young white dwarf with a
supersolar metallicity. G299.2-2.9 apparently shows an elongated, strong outflow-like ejecta feature.
This particular emission feature may suggest an asymmetric explosion or a significantly modified
environment, unlike the traditional picture of Type Ia supernova.