The yttria mould with diacetatozirconic acid as binder was introduced for directional solidification of TiAl alloy. The infiltration of Ti-47Al-2Cr-2Nb (at%) molten metal on the mould was evaluated and the mould contamination on the metal-alloy rods was investigated. The results indicate that the infiltration of alloy occurs on the inner layer of the mould only and no structural damage or exudate is observed after holding 30 min at 1550, 1600, 1650 °C, respectively. Two types of inclusions are explored in the alloy, they are Al2O3 and admixture inclusion composed of by Al2O3 and Y-Al-O and the scale and volume fraction of the inclusions significantly increase by rising of holding temperature. At 1650 °C for 30 min holding time, the foreign inclusions are distributed on the entire cross-section of the as-cast rod. The amount of the inclusions trend to decrease from the edge to the center of the rods at 1550, 1600 °C for 30 min. Moreover, on the region around 2500 μm to the surface of the as-cast rod at 1550 °C for 30 min, no obvious ceramic inclusion is discovered. The forming mechanism of inclusions in the alloy was analyzed.