Abstract: To study emission property and microstructure of Re doped cathode,the Sol-Gel combined with a two-step hydrogen reduction method was adopted to fabricate R5S5( 5% Sc₂O₃+ 5% Re₂O₇) codoped tungsten powder. The rare-earth doped matrix cathodes were prepared by the pressing,sintering,impregnating and ultra-sonic watering. Microstructure and emission property of cathodes were investigated by modern analysis techniques, such as SEM and UHV electron emission surveyor. The emission properties of R5S5 cathodes were excellent,i. e.,the current density J_div reaching 30. 14 A/cm² at 850 ℃_b. The local electric fields around the nanoparticles on the cathode surface increased,resulting in the improvement of emission property of the cathode.