  There are some points to notice in the dimensional reduction of the off-shell
supergravity. We discuss a consistent way of the dimensional reduction of
five-dimensional off-shell supergravity compactified on S^1/Z_2. There are two
approaches to the four-dimensional effective action, which are complementary to
each other. Their essential difference is the treatment of the compensator and
the radion superfields. We explain these approaches in detail and examine their
consistency. Comments on the related works are also provided.
