  We construct two and three-line shifts for tree-level amplitude with massless
and/or massive particles, and provide a method to construct general multi-line
shifts for all masses. We choose the massless-massive BCFW shift from these
shifts and examine its validity in renormalizable theories. Using such a shift,
we find that amplitudes with at least one massless vector boson are
constructible. This reveals the importance of gauge theory in the construction
of amplitudes with massive particles. We also find that this kind of amplitudes
have a cancellation related to group structure among different channels, which
is essential for constructibility. Furthermore, we show that in the limit of
large shift parameter $z$, the amplitude with four massive vector bosons, which
can include transverse massive vector particles, have structures proportional
to the amplitude with shifted vector particles replaced by Goldstone bosons in
the leading order. This is responsible for the failure of massive-massive BCFW
recursion relations in the amplitudes with four massive vector bosons.
