  The distillability of bipartite entangled state as seen by moving observers
has been investigated. It is found that the same initial entanglement for a
state parameter $\alpha$ and its "normalized partner" $\sqrt{1-\alpha^2}$ will
be degraded as seen by moving observer. It is shown that in the ultra
relativistic limit, the state does not have distillable entanglement for any
$\alpha$.
