  We study the sea quark contributions to the electromagnetic form factors of
$\Sigma$ baryons with nonlocal chiral effective theory. Both octet and decuplet
intermediate states are included in the one loop calculation.
$G_{\Sigma^{-}}^{u}$ and $G_{\Sigma^{+}}^{d}$ could be priority observables for
the examination of sea quark contributions to baryon structure because these
quantities are much larger than the strange form factors of nucleon. It will be
less difficult for lattice simulation to determine the sign of these pure sea
quark contributions unambiguously. In $\Sigma^0$, the light sea quark form
factors $G_{\Sigma^{0}}^{u}$ and $G_{\Sigma^{0}}^{d}$ are identical. Since the
light sea quark form factors in proton are different, it will be more
meaningful to compare lattice result of the light sea quark form factors in
$\Sigma^0$ with that obtained from effective field theory.
