Merrillia caloxylon is categorised as a rare plant with status vulnerable. This plant has been collective in Bogor Botanical Garden and planted at Vak. VIII.G.230 XXIV.A.180 and Vak. XXIV.196. these plant often produce flowers but never form a fruit. Seed propagation is more dificult therefore need improvement in vegetative propragation techniques. Air layering is the alternative method of vegetative propagation the size of these branches between 1-2 cm not use branches size 3cm or more. Moss and bamboo compost used in this treatment. The result showed that medium moss give a better effect on the growth of M.Caloxylon.