The　structural　and　magnetic　properties　of　La1-yTbyFe11.5Si1.5　compounds　have　been　investigated.　The　substituted　5　percent　of　Tb　has　remarkably　increased　the　maximum　entropy　change　(-Delta　S-M)　to　a　value　of　25.2　J/kg.K.　However,　a　further　increase　of　Tb　leads　to　a　monotonous　decrease　in　the　entropy　change,　mainly　due　to　phase　separation.　The　Tb　substitution　also　can　lower　the　thermal　and　magnetic　hysteresis　loss　of　the　system.　Another　feature　of　this　replacement　is　that,　with　Tb　content　higher　than　10　percent,　the　Curie　temperature　(T-C)　starts　to　increase　and　reaches　197　K　when　30　percent　of　La　is　substituted.　These　results　indicate　that　La1-yTbyFe11.5Si1.5　may　be　a　promising　candidate　for　magnetic　refrigeration　material　in　certain　temperature　range.　(C)　2018　Elsevier　B.V.　All　rights　reserved.