  The phase transition and jet quenching parameter ${\hat q}$ have been
investigated in the framework of dynamical holographic QCD model. It is found
that both the trace anomaly and the ratio of the jet quenching parameter over
cubic temperature ${\hat q}/T^3$ show a peak around the critical temperature
$T_c$, and the ratio of jet quenching parameter over entropy density ${\hat
q}/s$ sharply rises at $T_c$. This indicates that the jet quenching parameter
can characterize the phase transition. The effect of jet quenching parameter
enhancement around phase transition on nuclear modification factor $R_{AA}$ and
elliptic flow $v_2$ have also been analyzed, and it is found that the
temperature dependent jet quenching parameter from dynamical holographic QCD
model can considerably improve the description of jet quenching azimuthal
anisotropy as compared with the conformal case.
