Let
f be a non-invertible irreducible Anosov map on
d-torus. We show that if the stable bundle of
f is one-dimensional, then
f has the integrable unstable bundle, if and only if, every periodic point of
f admits the same Lyapunov exponent on the stable bundle with its linearization. For higher-dimensional stable bundle case, we get the same result on the assumption that
f is a
-perturbation of a linear Anosov map with real simple Lyapunov spectrum on the stable bundle. In both cases, this implies if
f is topologically conjugate to its linearization, then the conjugacy is smooth on the stable bundle.