We present the results of a highly sensitive (${sim}10$ mK rms) survey toward the central parts of 22 barred spiral galaxies in $^{12}CO(1-0)$ line using the NRAO 12m telescope at Kitt Peak. Seven of the target galaxies were detected in CO; NGC 3686 has been detected with CO for the first time. We estimated central CO fluxes of $50{sim}1000;Jy;km;s^{-1}$ and molecular gas masses of $10^7{sim}10^8;M_{odot}$ for those galaxies.