The Ti-43Al-9V-0.3Y alloy was manufactured by electrode induction melting gas atomization (EIGA) and hot isostatic pressing (HIPing). Effect of HIPing temperature and powders particle size on microstructure and properties of this alloy were investigated. The TiAl powders and HIPed samples were characterized by field emission scanning electron microscopy (FESEM), energy dispertive spectrum (EDS), X-ray diffraction (XRD), quantitative metallugraphy ( QM) and mass spectrometer (MS). The results indicate that the TiAl alloy powders mainly consist of β/B2 phase. After hot isostatic pressing, the alloy mainly consists of γ and β/B2 phases. In addition, the powder and HIPed state alloys both contain a small amount of YAl2 and Y2O3 phases. After 1000-1260℃/150MPa/3h HIPing, the TiAl alloy microstructure is near γ, which is mainly comprised of γ phase and β/B2 phase. With the HIPing temperature increasing, the size of γ phase as well as the tensile elongation increased, but the tensile strength decreased. The Ar content and hollow powder quantity reduced accompanied by the powder particle size decreased. The TiAl alloy powders were sieved into three particle size range (<53μm, 53-105μm, 105-250μm), and then consolidated by HIPing at 1200°C for 3hrs under 150MPa argon pressure followed by furnace cooling. The microstructure and tensile strength of the alloy did not change significantly with the particle size, but the high temperature tensile elongation of the alloy increased obviously with the decrease of the particle size.