  The strangeness $S=-2$ baryon-baryon interaction is investigated directly
from the fundamental theory of the strong interaction, QCD. The HAL QCD method
enables us to extract baryon interactions from the Nambu-Bethe-Salpeter wave
functions without using any experimental information. We present our latest
result on the $S = -2$ baryon interactions and discuss the H-dibaryon state
using potentials which are calculated by using the (almost) physical point
gauge configurations with large lattice volume of$(8.1{\rm{fm}})^4$ generated
on the K-computer.
