  The interacting dark matter (IDM) scenario allows for the acceleration of the
Universe without Dark Energy. We constrain the IDM model by using the newly
revised observational data including $H(z)$ data and Union2 SNe Ia via the
Markov chain Monte Carlo method. When mimicking the $\Lambda$CDM model, we
obtain a more stringent upper limit to the effective annihilation term at
$\kappa C_1\approx 10^{-3.4}\rm{Gyr}^{-1}$, and a tighter lower limit to the
relevant mass of Dark Matter particles at $M_x\approx 10^{-8.6}\rm{Gev}$. When
mimicking the $w$CDM model, we find that the effective equation of state of IDM
is consistent with the concordance $\Lambda$CDM model and appears to be most
consistent with the effective phantom model with a constant EoS for which
$w<-1$.
