  A controlled quantum dense coding scheme is investigated with a four-particle
non-maximal quantum channel. The amount of classical information is shown to be
capable of being controlled by the controllers through adjustments of the local
measurement angles and to depend on the coefficients of the quantum channel; in
addition, the four particles are distributed in two inverse ways in such an
quantum channel. A restricted condition for distributing the particles to
realize quantum dense coding in an arbitrary ($N+2$)-particle quantum channel
is proposed.
