  We report on the upper critical field B_c2 of a superconducting LiFeAs single
crystal with T_c~16 K, determined from magnetic torque measurements in
dc-magnetic fields up to 35 T and at temperatures down to 0.3 K. B_c2 at 0.3 K
is obtained to be 26.4 T and 15.5 T for the applied field B_a||ab and B_a||c,
respectively. The anisotropy parameter $\Gamma$=$B_c2^ab / B_c2^c$ is ~ 3 at
T_c and decreases to 1.7 as $T \rightarrow 0$, showing rather isotropic
superconductivity. While B_c2 is orbitally-limited for B_a||c, the
spin-paramagnetic effect is evident in the temperature dependence of B_c2 for
B_a||ab
