  To study drag force on a moving heavy quark through a plasma, we use a
deformed AdS space-time, in which deformation parameter $c$ describes
non-conformality in AdS/QCD. In this case the quark is mapped to a probe string
in the AdS space. Considering probable contribution of deformation parameter in
the probe string, we apply a general form of c-dependent string ansatz in the
drag force computation. Then we find the acceptable value of this parameter as
it satisfies QCD calculations. Using this result, we also discuss diffusion
constant which is in agreement with phenomenological result for
non-relativistic limit. Also we show that while in absence of deformation
parameter, probe string is a strictly increasing function of radial coordinate,
the c-dependent probe string has a maximum value versus $z$.
