The　in-situ　formed　SiC/Al4SiC4　joining　layer　was　used　to　join　monolithic　SiC　using　an　electric　field-assisted　sintering　technique.　A　multiphase　powder　of　Al4C3/SiC/Al4SiC4　was　used　as　the　initial　joining　material　to　obtain　the　in-situ　reaction　layer　of　SiC/Al4SiC4　via　the　appropriate　interface　reactions.　The　bending　strength　as　high　as　240.5　±　6.6　MPa　was　obtained　for　the　sample　joined　at　1800　°C,　which　was　higher　than　the　strength　of　the　un-joined　SiC　matrix.　Sound　joints　were　obtained　when　Al4C3　was　completely　transformed　to　Al4SiC4,　and　a　fully　dense　SiC/Al4SiC4　joining　layer　was　consolidated.　The　integration　of　the　joining　layer　with　the　SiC　matrix　was　improved　by　a　high　amount　of　liquid　phase　formed　at　the　interface.　The　proposed　SiC/Al4SiC4　joining　layer,　with　good　thermal　matching　with　SiC　matrix,　shows　a　great　potential　to　be　applied　as　a　joining　material　for　SiC-based　ceramic　matrix　composites.　©　2020　Elsevier　Ltd