Abstract: With a physical model developed for the top-bottom-side (TBS) blown converters, the effects of blowing process parameters on stirring and mixing behavior in the converter bath were investigated experimentally. The results showed that the flowrate of side-blowing gas affects greatly the bath mixing time, and a critical value of side-blowing gas flowrate is found in the TBS blown converters. Horizontal stirring effect in the bath is intensified gradually and the mixing time is shortened when the side-blowing gas flowrate is increased but lower than the critical value. But, when the side gas flowrate reaches the critical value, the mixing time in the bath drops considerably and, with the side-blowing gas flowrate further enhanced, it no longer changes obviously. A side nozzle with small section area as possible is recommended under the precondition that large enough side-blowing gas flowrate can be provided. In addition, an appropriate bottom-blowing gas flowrate is beneficial to the mixing in the TBS blown converter bath, and the change of top lance height or top-blowing gas flowrate affects unobviously the mixing time in the TBS blown converter bath.