  Each closed oriented 3-manifold $M$ is naturally associated with a set of
integers $D(M)$, the degrees of all self-maps on $M$. $D(M)$ is determined for
each torus bundle and torus semi-bundle $M$. The structure of torus semi-bundle
is studied in detail. The paper is a part of a project to determine $D(M)$ for
all 3-manifolds in Thurston's picture.
