  We investigate the magnetic susceptibility of the QCD vacuum, based on the
instanton vacuum. Starting from the instanton liquid model for the instanton
vacuum, we derive the light-quark partition function $Z[V,T,\hat{m}]$ in the
presence of the current quark mass $\hat{m}$ as well as the external Abelian
vector and tensor fields. We calculate a two-point correlation function
relevant for the magnetic susceptibility and derive it beyond the chiral limit.
We obtain for the different flavors the following magnetic susceptibility:
$\chi_{u,d}< i\psi_{u,d}^\dagger \psi_{u,d}>_0 \sim 40\sim45 {\rm MeV}$, while
$\chi_{s}< i\psi_s^\dagger \psi_s >_0 \simeq 6\sim 10 {\rm MeV}$ with the quark
condensate $<i\psi^\dagger \psi>_0$.
