  As one of the most fundamental physical phenomena, the anomalous Hall effect
(AHE) typically occurs in ferromagnetic materials but is not expected in the
conventional superconductors. Here, we have observed a giant AHE in kagome
superconductor CsV3Sb5 with transition temperature (Tc) of 2.7 K. The anomalous
Hall conductivity reaches up to 2.1*10^4 {\Omega}-1 cm-1 which is larger than
those observed in most of the ferromagnetic metals. Strikingly, the emergence
of AHE exactly follows the higher-temperature charge-density-wave (CDW)
transition with TCDW ~ 94 K, indicating a strong correlation between the CDW
state and AHE. The origin for AHE is attributed to enhanced skew scattering in
CDW state and large Berry curvature arose from the kagome lattice. These
discoveries make CsV3Sb5 as an ideal platform to study the interplay among
nontrivial band topology, CDW and unconventional superconductivity.
