Abstract: The α phase globularization is locally found in lamellar structure of Ti-5Al-2Zr-1Sn-1Mo-1V alloy after being treated at 950℃. Besides, clusters are found when the alloy is heat treated at different temperatures. The samples with clusters are accurately prepared by focused ion beam (FIB). The morphologies are observed and diffraction pattern is analyzed by TEM. The results show that nanoclusters in lamellar structure are composed of several Sn single crystal particles with the size of less than 100 nm.