The board plays a central role in monitoring the management on behalf of shareholders, yet the efficacy of board monitoring is difficult to determine. This study proposes using board attendance as a proxy measure of board supervisory quality and investigates the factors influencing board attendance, as well as their impact on firms� performance, by conducting a second-order regression analysis. The results show that board attendance decreases with multiple directorships, meeting frequency, and board size, indicating that busier directors and a more complex board combine to lower meeting attendance. The director shareholding rate and proportion of independent directors increase with board attendance, implying the convergence of interest among directors and companies and that strong external monitoring prompts higher board attendance. Finally, we find that higher board attendance enhances higher firm accounting performance, verifying that firms could view the attendance rate as an indication of the quality of the board supervision of these corporate monitors.