TC4 titanium alloy was brazed to 30CrMnSiNi2A ultra-high strength steel by Ti-37.5Zr-15Cu-10Ni and Ag-Cu28 brazing filler metals respectively. Microstructure and mechanical property of both brazed joints were analyzed comparatively. Results show that Ag-Cu28 brazed interface is composed of Ag(s,s) and intermetallic compounds in Ti-Cu system. Ag-Cu28 brazed joint has relatively high shear strength due to the exisitence of Ag based solid solution and the shear fracture shows the characteristics of ductile fracture. Ti-37.5Zr-15Cu-10Ni brazed interface consists of Ti-Zr solid solution and solidified brazing filler metals, which lead to the low hear strength of brazed joint. The shear fracture of Ti-37.5Zr-15Cu-10Ni brazed joint shows the characteristics of brittle fracture. Compared with Ti-based brazing filler metal, Ag-based brazing filler metal is suitable for brazing TC4 titanium / 30CrMnSiNi2A ultra-high strength steel dissimilar materials. Sound brazed joints with the shear strength of 125.52MPa can be attained at the brazing temperature of 830℃ with the bolding time of 15 min by Ag-Cu28 brazing filler metals.