  Deviation of the multiplicity distribution $P_q$ in small bin from its
Poisson counterpart $p_q$ is studied within the Ginzburg-Landau description for
second-order quark-hadron phase transition. Dynamical factor $d_q\equiv
P_q/p_q$ for the distribution and ratio $D_q\equiv d_q/d_1$ are defined, and
novel scaling behaviors between $D_q$ are found which can be used to detect the
formation of quark-gluon plasma. The study of $d_q$ and $D_q$ is also very
interesting for other multiparticle production processes without phase
transition.
