Two-phase flow in a water-air model of a continuous casting slab mold is studied using Particle Image Velocimetry technology. At low gas-loads (mass flow rate of gas/mass flow rate of liquid) fluid flow patterns of phases, gas and liquid, are different and with increases of this parameter both flow fields become similar. In the liquid phase, angles of the jet-root (in front of the SEN's ports) and jet core (main jet-body) are complex functions of the gas flow and casting rates. The first is decreased well below the angle of the SEN's port and the second is increased well above the same angle for all gas-loads. The jet-root angle increases, from small values, while the jet-core angle observes a maximum with the gas flow rate at any casting rate. The jet-core angle approaches to the angle of the SEN's port at high gas flow rates. Accumulation of bubbles is observed in the mold cavity when the casting rate is high at low or high flow rates of gas. Averaged bubble sizes depend on the coalescence-breakup kinetics, which vary with the gas-load. Liquid entrainment by gas to the flux is greatly increased with the casting rate even at low gas-loads. Further understanding of the two-phase flow dynamics should be attained in order to improve the boundary conditions of mathematical models.