An as-cast Ti-47AI-I Cr-2.5V plate was used to perform ambient tensile test. The metallography of the specimen exhibits typical lamellar structure with two-phase titanium aluminides. Monotonic tension tests under mechanical test systems of MTS-810 and Scanning Electron Microscope (SEM), along with a novel holder, were carried out regarding microstructure influence on crack initiation. Test results give the orientation preference of initiated cracks, i.e. 40 degrees, 60 degrees and 90 degrees. Furthermore, with respect to crystallography and a model of interface mechanics, related mechanisms are discussed.