  In this paper, we study the possibility of building Yang-Mills(YM) field dark
energy models with equation of state (EoS) crossing -1, and find that it can
not be realized by the single YM field models, no matter what kind of
lagrangian or initial condition. But the states of $-1<\omega<0$ and
$\omega<-1$ all can be naturally got in this kind of models. The former is like
a quintessence field, and the latter is like a phantom field. This makes that
one can build a model with two YM fields, in which one with the initial state
of $-1<\omega<0$, and the other with $\omega<-1$. We give an example model of
this kind, and find that its EoS is larger than -1 in the past and less than -1
at the present time. We also find that this change must be from $\omega>-1$ to
$<-1$, and it will go to the critical state of $\omega=-1$ with the expansion
of the Universe, which character is same with the single YM field models, and
the Big Rip is naturally avoided.

Astrophysics