  We consider the Reidemeister torsion associated with SL(2, C)-representations
of a knot group. A bifurcation point in the SL(2, C)-character variety of a
knot group is a character which is given by both an abelian SL(2,
C)-representation and a non-abelian one. We show that there exist limits of the
non-acyclic Reidemeister torsion at bifurcation points and the limits are
expressed by using the derivation of the Alexander polynomial of the knot in
this paper.
