  We compute the ring structure of Floer cohomology groups of Lagrangian torus
fibers in some toric Fano manifolds continuing the study of \cite{CO}. Related
$\AI$-formulas hold for transversal choice of chains. Two different
computations are provided: a direct calculation using the classification of
holomorphic discs by Oh and the author in \cite{CO}, and another method by
using an {\it analogue of divisor equation} in Gromov-Witten invariants to
thecase of discs.
  Floer cohomology rings are shown to be isomorphic to Clifford algebras, whose
quadratic forms are given by the Hessians of functions $W$, which turn out to
be the superpotentials of Landau-Ginzburg mirrors. In the case of $\CP^n$ and $
\CP^1 \times \CP^1$, this proves the prediction made by Hori, Kapustin and Li
by B-model calculations via physical arguments. The latter method also provides
correspondence between higher derivatives of the superpotential of LG mirror
with the higher products of $\AI$(or $\LI$)-algebra of the Lagrangian
submanifold.
