Recently an interest toward high density nuclear matter has been reconsidered 

and discussed rather seriously in various fields, in particular, in high-energy 

nuclear physics.
  In the present talk, I shall review, first, historical aspects in this field toward high 

density matter since 40 years ago, as viewed from my personal view.  Then, in the second, 

I will describe the current efforts of heavy-ion collisions both at RHIC and LHC. 

In the third, I discuss future possibilities in terms of “high-density nuclear matter” 

physics including neutron stars, together with our recent accelerator efforts at J-PARC.