  We consider certain elliptic threefolds over the projective plane (more
generally over certain rational surfaces) with a section in Weierstrass normal
form. In particular, over a del Pezzo surface of degree 8, these elliptic
threefolds are Calabi-Yau threefolds. We will discuss especially the generating
functions of Gromov-Witten and Gopakumar-Vafa invariants.
