  Vortex-lattice structures of antiferromagnetic spinor Bose-Einstein
condensates with hyperfine spin F=1 are investigated theoretically based on the
Ginzburg-Pitaevskii equations near $T_{c}$. The Abrikosov lattice with clear
core regions are found {\em never stable} at any rotation drive $\Omega$.
Instead, each component $\Psi_{i}$ $(i=0,\pm 1)$ prefers to shift the core
locations from the others to realize almost uniform order-parameter amplitude
with complicated magnetic-moment configurations. This system is characterized
by many competing metastable structures so that quite a variety of vortices may
be realized with a small change in external parameters.
