Fluctuations near the deconfinement phase transition boundary

In this talk I discuss how a first order phase transition may proceed in rapidly expanding partonic matter produced in a relativistic heavy-ion collision. The resulting picture is that a strong collective flow of matter will lead to the fragmentation of a metastable phase into droplets. If the transition from quark-gluon plasma to hadron gas is of the first order, it will manifest itself by strong nonstatistical fluctuations in observable hadron distributions. I discuss shortly existing experimental data on the multiplicity fluctuations.