The LaFe11.5Si1.5H1.3 interstitial compound has been prepared. Its Curie temperature TC (288K) has beenadjusted to around room temperature, and the maximal magnetic entropy change (|△S|~17.0J.kg-1.K-1 at TC) islarger than that of Gd (|△S|~ 9.8 J.kg-1.K-1 at TC=293K) by~73.5% under a magnetic change from 0 to ST. Theorigin of the large magnetic entropy change is attributed to the first-order field-induced itinerant-electron metamagnetictransition. Moreover, the magnetic hysteresis of LaFe11.5Si1.5H1.3 under the increase and decrease of the field is verysmall, which is favourable to magnetic refrigeration application. The present study suggests that the LaFe11.5Si1.5H1.3compound is a promising candidate as a room-temperature magnetic refrigerant.