  Asteroseismology is a unique tool to explore the internal structure of stars
through both observational and theoretical research. The internal structure of
pulsating hydrogen shell white dwarfs (ZZ Ceti stars) detected by
asteroseismology is regarded as the representative of all DA white dwarfs.
Observations for KUV~08368+4026, which locates in the middle of the ZZ Ceti
instability strip, have been carried out in 1999 and from 2009 to 2012 with
either single-site runs or multisite campaigns. Time-series photometric data of
about 300 hours were collected in total. Through data reduction and analysis,
30 frequencies were extracted, including four triplets, two doublets, one
single mode and further signals. The independent modes are identified as either
l=1 or l=2 modes. Hence, a rotation period of $5.52\pm 0.22$ days was deduced
from the period spacing in the multiplets. Theoretical static models were built
and a best fit model for KUV~08368+4026 was obtained with $0.692\pm0.002$ solar
mass, $(2.92\pm0.02)\times 10^{-3}$ solar luminosity and the hydrogen mass
fraction of $10^{-4}$ stellar mass.
