  Single crystals of Rb{0.8}Fe2Se2 are successfully synthesized with the
superconducting transition temperatures T_c{onset}= 31 K and T_c{zero}= 28 K. A
clear anomaly of resistivity was observed in the normal state at about 150 K,
as found in a similar system KxFe2Se2. The upper critical field has been
determined with the magnetic field along ab-plane and c-axis, yielding an
anisotropy of about 3.5. The angle dependent resistivity measured below T_c
allow a perfect scaling feature based on the anisotropic Ginzburg-Landau
theory, leading to a consistent value of the anisotropy which decreases from
about 3.6 at around T_c to 2.9 at 27 K. Comparing to the anisotropy determined
for Ba0.6K0.4Fe2As2 and Ba(Fe0.92Co0.08)2As2 using the same method, we find
that the present sample is more anisotropic and the Fermi surfaces with
stronger two dimensional characters are expected.
