  We consider the 8-supercharge 5d su(N) gauge theories from M-theory
compactified on elliptic Calabi-Yau threefolds. By matching the triple
intersection numbers in the elliptic Calabi-Yau with the 5d Chern-Simons
levels, we determine the charged matter contents for these theories. We show
that all these 5d theories can be lifted to 6d N = (1, 0) theories while
satisfying the anomaly cancellation equations. This suggests that the 5d
theories obtained from M-theory compactified on elliptic Calabi-Yau threefolds
have a natural 12d description, which as we know is F-theory. Furthermore, we
compute the Euler characteristics of the elliptic Calabi-Yau threefolds.
