Cambodia supports the largest remaining blocks of tropical dry forest in the Mekong region with some of the richest and most valuable habitats on Earth (WWW, 2008). We investigated a leaf and fruit litter supply by emergent tree Myristica iners (Myristicaceae) four years (2004.10-2008.09) in a Cambodian lowland evergreen forest. Basically, we observed leaf exchange on Feb.-Mar., flowering on Apr.-Jun., fruiting on Dec.-Mar. Female trees displayed a clear biennial fruiting, whereas male trees produced sterile flowers even in a non-fruiting year. A remarkable biennial leaf loss was found for female trees, which indicated that the leaves were retained two years. Male trees displayed less yearly variation in leaf phenology, at least, exhibited some leaf loss every year. Reproductive organs accounted for 71 % of total litter weights during the four study years. A 2006 reproductive event during provided 459 g C m^-2 and 5.2 g N m^-2 on the ground, whereas a series of leaf exchange provided only 44 g C m^-2 and 0.8 g N m^-2 in the fruiting year. In the non-fruiting year (2005 and 2007), leaf exchanges provided 118-207 g C m^-2 and 2.4-3.6 g N m^-2. The yearly variation in nutrient supply by the M. iners that dominated in a head area of watershed possibly affect productivity in downstream ecosystems.