  Millimeter sized ThCr$_2$Si$_2$-type CeNi$_2$As$_2$ single crystal was
synthesized by NaAs flux method and its physical properties were investigated
by magnetization, transport and specific heat measurements. In contrast to the
previously reported CaBe$_2$Ge$_2$-type CeNi$_2$As$_2$, the ThCr$_2$Si$_2$-type
CeNi$_2$As$_2$ is a highly anisotropic uniaxial antiferromagnet with the
transition temperature $T_N$=4.8 K. A field induced spin flop transition was
seen below $T_N$ when the applied $\textbf{B}$ is parallel to the
$\textbf{c}$-axis, the magnetic easy axis, together with a huge frustration
parameter $f=\theta_W/T_N$. A pronounced Schottky-like anomaly in specific heat
was also found around 160 K, which could be attributed to the crystalline
electric field effect with the excitation energies being fitted to
$\Delta_1=$325 K and $\Delta_2=$520 K, respectively. Moreover, the in-plane
resistivity anisotropy and low temperature X-ray diffractions suggest that this
compound is a rare example exhibiting a possible structure distortion induced
by the $4f$-electron magnetic frustration.
