Abstract: Electron beam weldingbrazing experiments of titanium to aluminum using AlSi5 filler wire were carried out in present paper. Microstructure and mechanical properties of welding joints were examined. The results showed that it was possible to join aluminum to titanium by electron beam welding with filler wire. Tensile strength reached 98.8 MPa, up to 96.7% of that of aluminum. The joint took on a typical weldingbrazing characteristic, which was composed of brazing joint at titanium side and welding joint at aluminum side. There was a Ti-Al intermetallic layer in the brazing joint with a thickness less than 2 μm, having weak impact on mechanical properties. Aluminum weld can be strengthened by dispersedly distributed IMCs. The lowest hardness value was in the HAZ, where fracture occurred during tensile test.