  The interplay between the thermal transport property and the topological
aspect is investigated in a spin-triplet chiral p-wave superconductor Sr2RuO4
with the strong two-dimensionality. We show the thermal Hall conductivity is
well described by the temperature linear term and the exponential term in the
low temperature region. While the former term is proportional to the so-called
Chern number directly, the latter is associated with the superconducting gap
amplitude of the gamma band. We also demonstrate that the coefficient of the
exponential term changes the sign around Lifshitz transition. Our obtained
result may enable us access easily the physical quantities and the topological
property of Sr2RuO4 in detail.
