Owing to the high liquidus temperature and reactivity, it is usually difficult to undercool liquid Ti-Al alloys and measure their thermophysical properties. Here, the surface tension of liquid Ti(80)Al(20) alloy is determined in the temperature range of 1706-2273 K by using oscillating drop method under electromagnetic levitation condition, and a maximum undercooling of 257 K (0.13 T(L)) is achieved. The measured surface tension of Ti(80)Al(20) alloy exhibits a linear dependence on temperature. Furthermore, based on the measured surface tension, the viscosity is also derived. (C) 2011 Elsevier B. V. All rights reserved.