A　blended　cementitious　material　consisting　of　cement　and　titanium　slag　in　a　mass　ratio　of　1:1　was　prepared　and　the　influence　of　varying　dosages　of　tetrakis　(2-hydroxyethyl)　ethylenediamine　(Theed)　on　the　strength　development　and　hydration　process　of　the　blended　systems　was　investigated.　The　hydration　process,　pore　structure　and　microstructure　at　different　ages　were　characterised　by　isothermal　conduction　calorimetry,　X-ray　diffraction,　thermogravimetric　analysis,　mercury　intrusion　porosimetry　and　scanning　electron　microscopy.　The　results　showed　that:　the　addition　of　Theed　(0.01-0.10%)　tended　to　improve　the　flexural　and　compressive　strength　of　the　blended　mortars;　the　addition　of　Theed　increased　the　hydration　degree　of　the　blended　cement　pastes　before　28　d　while　delaying　the　early　(before　6　h)　hydration,　as　indicated　by　isothermal　calorimetry　measurement;　the　pore　structure　of　the　blended　cement　pastes　after　curing　for　28　d　was　modified　by　Theed,　which　is　beneficial　for　strength　development;　the　pozzolanic　reaction　of　the　titanium　slag　was　enhanced　by　the　presence　of　Theed,　as　confirmed　by　the　portlandite　content,　pore　structure　measurements　and　morphological　observation.