  We study the possible bound states of the $K\bar K$ system in the
Bethe-Salpeter formalism in the ladder and instantaneous approximations. We
find that the bound states exist. However, these bound states have very small
decay widths. Therefore, besides the possible $K\bar K$ component, there may be
some other structures in the observed $f_0(980)$ and $a_0(980)$ .
