The　feasibility　of　utilising　a　shape　memory　alloy　(SMA)　in　a　tuneable　mass　damper　to　reduce　the　excessive　vibration　of　a　timber　floor　system　was　revealed　in　a　pilot　study.　In　real　cases,　the　in-service　excitations　on　a　timber　floor　can　be　complex,　and　more　frequencies　and　randomness　can　be　involved.　This　paper　aims　to　appraise　the　effectiveness　of　the　SMA-based　semi-active　TMD　in　a　real-scale　timber　floor　by　conducting　OPENSEES　numerical　analysis.　In　this　study,　the　human　walking　footfall-induced　vibration　is　considered　as　inputs.　When　the　floor-TMD　system　is　subject　to　walking,　which　involves　relatively　low　dominant　frequencies,　cooling　the　SMA　is　effective　in　reducing　the　off-tuning　excessive　vibration　caused　by　increasing　floor　mass.　Contrary　to　expectations,　there　is　no　increased　vibration　in　the　off-tuning　condition　caused　by　decreasing　floor　mass,　because　the　response　at　the　lower　frequency　range　decreases.　©　WCTE　2018　Committee.