As the excellent combination of strength and ductility, the high manganese steel has been used in the manufacturing field of automobile, liquefied natural gas (LNG) ship and oil and gas exploitation. On the other hand, due to the good damping capacity within a certain Mn content range, it has also been used to make components on the machines to reduce vibration and noise. So high manganese steel is considered to be a structural and functional integrated material with great application prospects. Many factors can affect the mechanical properties and damping capacity, such as chemical composition, grain size and heat treatments. Among these, carbon concentration has a complicated influence on them. For example, a high carbon concentration will improve mechanical properties, but in return deteriorate damping capacity. In order to acquire a material with good damping capacity and suitable strength and ductility, ultralow carbon Fe-19Mn-0.0017C (mass fraction, %) alloy was designed. The microstructural evolution and mechanical properties of the alloy during tensile process were investigated by means of OM, EBSD, TEM, XRD and tension test. The results show that Fe-19Mn shows deformation-induced martensite transformation, which changes from γ-austenite→ε-martensite transformation to ε-martensite→α'-martensite transformation as the amount of deformation increases. Analysis of the strain hardening rate (ln(dσ_true/dε_true)) combined with the fraction of constituent phases reveals that the transformation of ε-martensite→α'-martensite is more effective in improving work hardening rate than that of γ-austenite→ε-martensite. This is, on one hand, because of the lower strength of ε-martensite which is caused by the lack of carbon solution strengthening; and on the other hand, α'-martensite has higher hardness than ε-martensite, which can impede dislocation movement more effectively. In addition, {\mathrm{10}\stackrel{\text{?}}{\mathrm{1}}\mathrm{2}}<\stackrel{\text{?}}{\mathrm{1}}\mathrm{011}>ε deformation twins are formed to accommodate deformation of ε-martensite except for dislocation slip during tensile process. The combined action of transformation induced plasticity (TRIP) effects of γ-austenite→ε-martensite→α'-martensite transformation, dislocation slip of γ-austenite/ε-martensite/α'-martensite and {\mathrm{10}\stackrel{\text{?}}{\mathrm{1}}\mathrm{2}}<\stackrel{\text{?}}{\mathrm{1}}\mathrm{011}>ε deformation twinning makes Fe-19Mn with ultralow carbon concentration have an excellent combination of strength and ductility, whose tensile strength and total elongation can reach 722 MPa and 31%, respectively.