  In order to investigate the anisotropic magnetic properties of
CeAg$_2$Ge$_2$, we have successfully grown the single crystals, for the first
time, by high temperature solution growth (flux) method. We have performed a
detailed study of the grown single crystals by measuring their electrical
resistivity, magnetic susceptibility, magnetization, specific heat and
magnetoresistance. A clear anisotropy and an antiferromagnetic transition at
$T_{\rm N}$ = 4.6 K have been observed in the magnetic properties. The magnetic
entropy reaches $R$ ln 4 at 20 K indicating that the ground state and the first
excited state are very closely spaced (a quasi-quartet state). From the
specific heat measurements and crystalline electric field (CEF) analysis of the
magnetic susceptibility, we have found the level splitting energies as 5 K and
130 K. The magnetization measurements reveal that the a-axis is the easy axis
of magnetization and the saturation moment is $\mu_{\rm s}$ = 1.6 $\mu_{\rm
B}$/Ce, corroborating the previous neutron diffraction measurements on a
polycrystalline sample.
