  We present a QCD based interpretation of heavy quark fragmentation which
utilizes the heavy quark mass expansion. By distinguishing between perturbative
and non-perturbative QCD effects, we show how to reliably extract mass
independent parameters characterizing the fragmentation function. Because these
parameters are quark mass independent, this procedure should permit tests of
heavy quark symmetry. Furthermore, we show that heavy quark mass corrections
vanish at order $m^2/Q^2$ in QCD. There also exist higher twist corrections of
order $\Lambda m/Q^2$ and ${\alpha_{QCD}\over\pi} {m^2\over Q^2} \ln (Q^2/m^2)$
which we relate to the leading twist fragmentation function.
