  Planets and planet candidates are subjected to great investigation in recent
years. In this study, we analyse 20 planet and planet-candidate host stars at
different evolutionary phases. We construct stellar interior models of the host
stars with the MESA evolution code and obtain their fundamental parameters
under influence of observational asteroseismic and non-asteroseismic
constraints. Model mass range of the host stars is 0.74-1.55 ${\rm M}_\odot$.
The mean value of the so-called large separation between oscillation
frequencies and its variation about the minima show the diagnostic potential of
asteroseismic properties. Comparison of variations of model and observed large
separations versus the oscillation frequencies leads to inference of
fundamental parameters of the host stars. Using these parameters, we revise
orbital and fundamental parameters of 34 planets and four planet candidates.
According to our findings, radius range of the planets is 0.35-16.50
$\mathrm{R}_{\oplus}$. The maximum difference between the transit and revised
radii occurs for Kepler-444b-f is about 25 per cent.
