Nepenthes rajah usually grows in open, grassy clearings on old land slips and flat ridge tops, particularly in areas of seeping ground water, where the soil is loose and permanently moist.
Nepenthes rajah has an altitudinal distribution of 1500-2650 m a.s.l.[REF][REF] and is thus considered an (ultra) highland or Upper Montane plant [REF].