  The focal submanifolds of isoparametric hypersurfaces in spheres are all
minimal Willmore submanifolds, mostly being $\mathcal{A}$-manifolds in the
sense of A.Gray but rarely Ricci-parallel (\cite{QTY},\cite{LY},\cite{TY3}). In
this paper we study the geometry of the focal submanifolds via Simons formula.
We show that all the focal submanifolds with $g\geq3$ are not normally flat by
estimating the normal scalar curvatures. Moreover, we give a complete
classification of the semiparallel submanifolds among the focal submanifolds.
