  We consider the two point correlation function of scalar current in QCD sum
rules approach to estimate the overlap amplitude of $a_0$ meson. We then employ
QCD sum rules to calculate the coupling constants g$_{\omega a_0\gamma}$ and
g$_{\rho a_0\gamma}$ by studying the three point ${a_0\omega\gamma}$- and
${a_0\rho\gamma}$-correlation functions.
