Mn1.1Fe0.9P0.8Ge0.2Bx　(x=0,　0.02,　0.03,　0.04)　compounds　were　prepared　by　mechanical　milling　and　subsequent　spark　plasma　sintering　(SPS)　technique.　Their　crystal　structure　was　investigated　by　XRD　and　the　magneticaloric　properties　were　measured　by　DSC　and　VSM.　Results　show　that　Mn1.1Fe0.9P0.8Ge0.2Bx　(x=0,　0.02,　0.03,　0.04)　compounds　possess　a　hexagonal　Fe2P-type　crystal　structure.　The　lattice　parameters　a　and　c　are　changed　noticeably　with　the　increase　of　B,　and　c/a　ratio　decreases　firstly　and　then　increases.　There　is　a　nonlinear　relationship　between　Curie　temperature　as　well　as　the　entropy　change　and　the　content　of　B.　The　compound　achieves　the　best　magneticaloric　properties　in　this　system　when　x=0.02.　The　Curie　temperature　increases　from　253　K　for　x=0　to　263　K,　and　thermal　hysteresis　decreases　from　23　K　to　19　K.　The　maximum　value　of　the　magnetic　entropy　change　increases　from　28.7　to　32.6　J/kg.K　for　a　field　change　from　0　to　2　T.