Iron-rich　intermetallic　compound　Sm2Fe17N3　is　considered　to　be　a　highly　promising　candidate　for　newgeneration　permanent　magnetic　materials.　Here,　the　Ti-substituted　Sm-2(Fe,　Ti)(17)N-3　alloys　were　synthesized　using　reduction-diffusion　and　nitridation.　The　microstructure　and　magnetic　properties　of　Sm-2(Fe,　Ti)(17)　and　its　nitrides,　in　relation　to　the　effect　of　Ti　substitution,　were　systematically　investigated　through　a　comprehensive　experimental　approach　combined　with　first-principles　calculations.　It　was　revealed　that　the　Ti　substitution　is　very　effective　in　particle　refinement　of　Sm-2(Fe,　Ti)(17).　The　Rietveld　analysis　of　X-ray　data　demonstrated　an　expansion　in　the　unit　cell　volume　of　Sm-2(Fe,　Ti)(17)　phase　with　increasing　Ti　content.　Subsequent　nitridation　experiments　highlighted　the　beneficial　impact　of　an　appropriate　Ti　addition　on　the　enhancement　of　both　coercivity　and　remanence　in　Sm-2(Fe,　Ti)(17)N-3　magnetic　powder.　The　highest　coercivity　of　8.9　kOe　was　achieved　in　the　sample　with　a　Ti/Fe　mole　ratio　of　0.04.　Furthermore,　the　possible　crystallographic　occupancy　of　Ti　and　its　effect　on　the　phase　stability　are　investigated　using　first-principles　calculations.　Our　results　indicated　that　the　phase　stability　is　influenced　by　the　synergistic　effect　of　Ti　substitution　atoms　and　interstitial　N　atoms.　The　significance　of　this　study　lies　in　its　implications　for　the　development　of　advanced　permanent　magnetic　materials　through　reductiondiffusion　technology.