The sectionalization of conventional bubble columns by perforated trays into trayed bubble columns (TBCs) has much potential in biochemical and petroleum refining processes, as an effective way to improve the gas-liquid contacting efficiency and reduce the liquid backmixing. In this work, the effects of tray geometry, superficial gas velocity, and superficial liquid velocity on the overall gas holdup have been investigated. It was determined that the trays significantly increase the overall gas holdup. The tray hole diameter and superficial gas velocity were determined to be the most important factors.