  A number of empirical correlations that allows us to calculate the effective
temperature and surface gravity for a set evolved post-AGB and RV Tauri stars
are determined using as calibrators the intrinsic colours of 2MASS (Two Micron
All Sky Survey) photometry. We have analyzed a total sample of 36 stars where
25 are post-AGB stars and 11 are RV Tauri stars, respectively. A group of 11
stars with parallaxes measures were used as calibrators of the absolute
magnitude. The result for T$_{\rm eff}$ and log g from intrinsic colours
(J-H)$_{0}$ and (H-K$_{s}$)$_{0}$ at the near-infrared pass bands reach a
dispersion of 220 K and 0.27, respectively. We can estimate the absolute
magnitude using the intrinsic colour in the near-infrared band with an
uncertainty of 0.28 mag. This indicates that (J-H)$_{0}$ and (H-K$_{s}$)$_{0}$
show sensitivity to the absolute magnitude.
