We present our analysis of the Suzaku data of four typical Dwarf Novae (DNe), U Gem, SS
Cyg, V893 Sco and Z Cam. A fluorescent iron Kαline bears essentially important
information about the geometry of an X-ray-emitting hot plasma and a cold reflector,
such as the surfaces of the white dwarf (WD) and the accretion disk (AD).  In
quiescence, our spectral simulation, including reflection from the WD surface and the
AD, has revealed that the X-ray-emitting hot plasma, which is assumed to be a torus
centered on the WD with an infinitely small cross-sectional area, is located near the
entrance of the boundary layer (BL) which is the region between the WD surface and the
inner edge of the AD. The hot plasma is located in the region smaller than 1.1-1.4 RWD
for all the four DNe. The result suggests that the accreting matter is heated up close
to the maximum temperature immediately after the matter enters the BL. The matter
probably expands precipitously at the entrance of the BL and leaves off the disk plane
to reach the height comparable to the radial distance of the plasma torus from the
center of the WD. In outburst of SS Cyg, on the other hand, our spectral analysis favors
the picture that the optically thick disk reaches the WD surface. In addition, the
plasma distributes above the disk like coronae as suggested by a previous study and the
90% upper limit of the coronae radial position is 1.2 RWD.  We have also investigated
the relationship between the parameters of the hot plasma of BL and the fundamental
parameters of the binary system, such as mass accretion rate, density, and orbital
period in quiescence. The results show that the higher the mass accretion rate, the
higher the density, suggesting the better cooling efficiency in the optically thick AD,
and the closer the inner edge of the AD is to the surface of WD. We remark that the mass
accretion rate is known to be higher for longer orbital periods system (Nakaniwa Doctor
thesis). This is because the longer orbital period systems lose its orbital angular
momentum with a stellar wind from the companion star in addition to the gravitational
wave. Since such system has a higher density AD, and the disk appears to be closer to
the WD surface.