  We observed surface acoustic wave (SAW) propagation on a multiferroic
material CuB$_2$O$_4$ with use of two interdigital transducers (IDTs). The
period of IDT fingers is as short as 1.6 $\mu$m so that the frequency of SAW is
3 GHz, which is comparable with that of magnetic resonance. In
antiferromagnetic phase, the SAW excitation intensity varied with the magnitude
and direction of the magnetic field, owing to the dynamical coupling between
SAWs and antiferromagnetic resonance of CuB$_2$O$_4$. The microscopic mechanism
is discussed based on the symmetrically allowed magentoelastic coupling.
