  We present {\em ASCA} results of the pair clusters A399 and A401. The region
between the two clusters exhibits excess X-rays over the value expected with a
simple superposition of the two clusters. We see, however, no temperature rise
at the merging front; the temperature is near the average of those in the inner
regions of the two clusters. These indicate that the two clusters are really
interacting but it is not strong at present.
  The inner regions of the two clusters show no radial variations of
temperature, abundance and absorption values. We set upper-limits of mass
deposition rate of cooling flow to be $\dot{M}<35\;\rm M_{\odot}yr^{-1}$ and
$\dot{M}<59\;\rm M_{\odot}yr^{-1}$ for A399 and A401, respectively. A hint of
azimuthal variation of the temperature is also found.
