  The twistor--like formulation of the type IIA superstring $\sigma$--model in
D=10 is obtained by performing a dimensional reduction of the recently proposed
twistor--like action of the supermembrane in D=11. The superstring action is
invariant under local, worldsheet $(n,n)$ supersymmetry where $3\leq n \leq 8$
and is classical equivalent to the standard Green--Schwarz action (at least for
$n=8)$
