Advanced intermetallic β-solidifying γ-TiAl-based alloys have various potential applications in the aerospace and automobile industries due to their low density, functionality at higher temperatures, and high specific strength/modulus. The crucial aspect that needs to be considered when developing a new β-solidifying γ-TiAl alloy is to clarify the influence law of β-stabilizer elements on the phase transformation behavior of γ-TiAl alloys. In this work, the impact of W contents (0.5%-1.0%, atomic fraction) on the phase transformation behavior and microstructure characteristics of Ti-42Al-5Mn-xW (atomic fraction) alloy with low cost and superior temperature workability was systematically investigated. The findings demonstrate that there were minor changes in the β-phase single region temperature (T_β ) and γ phase solvus temperature (T_γ-solv); furthermore, the eutectoid reaction temperature (T_eut) increases with the W content from 0.5% to 1.0%. Addition of W influences the solid phase transformation pathway to a certain extent. When the concentration of W increases to 0.5%, the equilibrium phase of the alloy at near service temperature gradually changes from α₂ + γ + Laves to β_o + α₂ + γ + Laves. Additionally, W addition will also have a substantial effect on the lamellar microstructure. The volume fraction of lamellar microstructure considerably decreased after alloying with (0.5%-1.0%)W for Ti-42Al-5Mn alloy when being treated in the (γ + α + β) triple-phase region followed by furnace cooling. Increasing the W content to 0.8% and 1.0% results in the development of γ and β_o grain phases with almost complete removal of α₂/γ lamellar structures. However, the W-free and W-bearing Ti-42Al-5Mn alloys show near complete lamellar structures when treated in (α + β) two-phase region followed by furnace cooling. Furthermore, when the content of W increased from 0.5% to 1.0%, an equiaxed grain structure with refined lamellar colonies is typically obtained.