In　this　paper,　we　study　the　effects　of　Pr　substitution　on　the　hydrogenating　process　and　magnetocaloric　properties　of　La1-x　PrxFe11.4Si1.6Hy　hydrides.　The　powder　x-ray　diffraction　patterns　of　the　La1-x　PrxFe11.4Si1.6　and　its　hydrides　show　that　each　of　the　alloys　is　crystallized　into　the　single　phase　of　cubic　NaZn13-type　structure.　There　are　hydrogen-absorbing　plateaus　under　0.4938　MPa　and　0.4882　MPa　in　the　absorbing　curves　for　the　La-0.8　Pr0.2Fe11.4Si1.6　and　La0.6Pr0.4Fe11.4Si1.6　compounds.　The　releasing　processes　lag　behind　the　absorbing　process,　which　is　obviously　different　from　the　coincidence　between　absorbing　and　releasing　curves　of　the　LaFe11.4Si1.6　compound.　The　remnant　hydrogen　content　for　La0.6Pr0.4Fe11.4Si1.6　is　significantly　more　than　that　for　La0.8Pr0.2Fe11.4Si1.6　after　hydrogen　desorption,　indicating　that　more　substitutions　of　Pr　for　La　are　beneficial　to　retaining　more　hydrogen　atoms　in　the　alloys.　The　values　of　maximum　magnetic　entropy　change　are　14.91　J/kg　center　dot　K　and　17.995　J/kg　center　dot　K　for　La0.8Pr0.2Fe11.4　si(1.6)H(0.13)　and　La0.6Pr0.4Fe11.4Si1.6　H-0.87,　respectively.