  The progress over the last years in modelling the atmospheres and winds of PN
central stars is reviewed. We discuss the effect of the inclusion of the
blanketing by millions of metal lines in NLTE on the diagnostics of
photospheric and stellar wind lines, which can be used to determine stellar
parameters such as effective temperature, gravity, radius, mass loss rate and
distance. We also refer to recent work on the winds of massive O-type stars,
which indicates that their winds are possibly inhomogeneous and clumped. We
investigate implications from this work on the spectral diagnostics of PN
central stars and introduce a method to determine wind clumping factors from
the relative strengths of Halpha and HeII 4686. Based on new results we discuss
the wind properties of CSPN.
