  We investigate the interaction between H-dibaryons employing a quark cluster
model with a one-gluon-exchange potential and an effective meson exchange
potential (EMEP). A deeply-bound state of two H-dibaryons due to the medium
range attraction of the EMEP is obtained. The bound H--H system has a size of
about 0.8 $\sim$ 0.9 fm because of the short-range repulsion generated by the
color-magnetic interaction and the Pauli principle.
