Abstract: The torsional tuned liquid column damper (TTLCD) is a cost-effective passive device for reducing the torsional response of a plan-asymmetric building under wind or seismic load. In this paper, the equations of relative liquid motion in three kinds of TTLCDs, as well as the control forces with the reference point and various inclined angles of the upright columns were derived. The optimal TTLCD control parameters were given through transforming method of the TTLCD-structure equivalent to a TTMD-structure system using Den Hartog or Ikeda formulas. Finally, the TTLCD design method was evaluated and the TTLCD design process was described. The numerical results of a four-storey plan-asymmetric structure show that TTLCDs can effectively mitigate earthquake-induced coupled flexural torsional responses and that the proposed method is feasible.