  Taking the 3-3-1 models (with $SU(3)_c \otimes SU(3)_L \otimes U(1)_Y$ gauge
group) as examples, we study that a class of new physics models with extended
gauge group could undergo one or several first-order phase transitions
associated with the spontaneously symmetry breaking processes during the
evolution of the universe, which can produce detectable phase transition
gravitational wave (GW) signals at future GW experiments, such as LISA, BBO,
DECIGO, SKA and aLIGO. These GW signals can provide new sources of GWs with
different peak frequencies, and can be used to probe the evolution history of
the universe.
