  High-field electron spin resonance (ESR) measurements have been performed on
vesignieite BaCu$_3$V$_2$O$_8$(OH)$_2$, which is considered as a nearly ideal
model substance of $S$=1/2 kagome antiferromagnet, in the temperature region
from 1.9 to 265 K. The frequency region is from 60 to 360 GHz and the applied
pulsed magnetic field is up to 16 T. Observed g-value and linewidth show the
increase below 20 K, which suggest the development of the short range order.
Moreover, a gapless spin liquid ground state is suggested from the
frequency-field relation at 1.9 K.
