In this lecture we review recent development in non-perturbative QCD r
elated to instantons. The ''instanton liquid model'' was shown to repr
oduce not only the basic vacuum parameters (the condensates) but even
hadronic correlators. New phenomenological information obtained from l
attice simulations also confirm it. Meanwhile the model itself was dev
eloped into a self-consistent approach, allowing in practice keep 't H
ooft interaction to all orders and also was generalized to non-zero te
mperatures and high densities. In both case chiral restoration phase t
ransition is a structural transition from a relatively random instanto
n liquid to a gas of a strongly correlated instanton-anti-instantons,
at finite T they are pairs (or ''molecules'') and at high density they
are ''polymers'', or bound diquarks.