Abstract: Litterfall and element return dynamic and leaf consumption by animals were studied in humid seasonal rainforest in Menglun, Xishuangbanna, Southwesten China. 1. The litterfall was l1.29+l.96t/ha·a, and the amount of litterfall component was (t/ha·a±S. E.): for leaves, 7.41±0.82; wood (≤2 cm diameter), 2.16±1.78; flowers, 0.223±0.13; fruits, 0.7244±0.456 and mixed matter (includs plant trash, wastes of animals and died animal bodies from canopy), 0.77±0.18. A marked peak of litterfall occurred during a March-April period of the late dry season. 2. Large wood litterfall (>2 cm diameter) was measured twice during rainy season and dry season, the large wood litterfall mean was 0.82t/ha·a. 3. Returns (kg/ha·a) of the elements to the forest floor in the litterfall were ranged Ca (146.4) > N (57.3) > Mg (39.0) 3> K(31.2) > P (6.33) > Mn (5.49) 2> A1(4.40) > Fe(1.92) > Zn(0.56) > Cu (0.24).and a marked peak of element return coincided with the litterfall's. 4. The leaf area eaten by animals accounted for 16.2% of the total leaf area.

Key words: Rain forest, Litterfall, Foliage consumption