  We report here on the observation of Kes 27, a proto-typical mixed-morphology
SNR, using ASCA. It clearly shows a filled-center structure in the X-ray region
while a shell structure in the radio region. There are two radio bright
regions: one is in the center, while the other is in the east rim. The X-ray
intensity peak coincides well with the radio bright region at the center. The
X-ray spectrum was well-fitted by a collisional ionization equilibrium model
with solar abundances. Taking into account the ionization parameter (>10^{12}
cm^{-3} s) and the plasma density (0.39 cm^{-3}), we found that the age of the
SNR is longer than 8x10^4 yr. The hardness ratio map indicates that the inner
region shows a harder spectrum than that in the outer region, which does not
come from the heavier interstellar absorption feature, but from the higher
temperature. There is a temperature gradient from the innner region (0.84 keV)
toward outer region (0.59 keV), indicating that the thermal conduction does not
play an important role.
