  We propose a new method to extract the light quark mass ratio $m_u/m_d$ using
the $\Upsilon(4S)\to h_b\pi^0(\eta)$ bottomonia transitions. The decay
amplitudes are dominated by the light quark mass differences, and the
corrections from other effects are rather small, allowing for a precise
extraction. We also discuss how to reduce the theoretical uncertainty with the
help of future experiments. As a by-product, we show that the decay
$\Upsilon(4S)\to h_b\eta$ is expected to be a nice channel for searching for
the $h_b$ state.
