  The non-local vacuum condensates of QCD describe the distributions of quarks
and gluons in the non-perturbative QCD vacuum. Physically, this means that
vacuum quarks and gluons have nonzero mean-squared momentum, called virtuality.
In this paper we study the quark virtuality which is given by the ratio of the
local quark-gluon mixed vacuum condensate to the quark local vacuum condensate.
The two vacuum condensates are obtained by solving Dyson-Schwinger Equations of
a fully dressed quark propagator with an effective gluon propagator. Using our
calculated condensates, we obtain the virtuality of quarks in the QCD vacuum
state. Our numerical predictions differ from the other theoretical model
calculations such as QCD sum rules, Lattice QCD and instanton models.
