  Let $X$ be a smooth scheme over a perfect field $k$ of positive
characteristic. M.V.~Nori and V.~Srinivas studied infinitesimal liftings of
Frobenius morphism $F:X\to X$. Namely, given a Frobenius lifting $F_Y: Y\to Y$
over $W_{n-1}(k)$ the obstruction of lifting $F_Y$ over $W_n(k)$ is a class in
$H^1(X, T_X\tensor B_1\Omega^1_{X/k})$. We give a modified version of their
theory and applications, in which we consider lifting $(n-1)$th iterated
Frobenius $F^{n-1}:X\to X$ directly over $W_n(k)$.
