  Using the SNe Ia data we determine the three parameters in the power-law
expanding universe model with time-dependent power \cite{W}. Inputting $H_0$
and $t_0$, then we find the $\dot{a}-t$ evolution curve with $m=5.0$ and
$q_0=-0.90$ can fit very well to that from SNe observation data. The model
predicts the transition redshift $z\simeq0.38$. The dark energy deduced from
this model have phantom property but the universe doesn't encounter the Big Rip
singularity. Assuming that this model with the three parameters is valid for
the future universe, then we predict that the total energy density of the
universe is decreasing and will soon reach its minimum.
