Abstract: The evergrean breadleaved forest in Qiping forest farm is a secondary south subtropical forest dominated by Schima supcrba. This paper focuses on the quantitative dynamics, composition and main chemical components of litterfalls:(1)the annual total amount of litterfalls is 8.385t.ha^-1, and the percentages of leaves, twigs and fruits-flowers are 51.75%, 26.11% and 22.14% respectiveIy.(2)the annual quantitative variation of litterfall is unobvious compared with seasonal variations, which is highest in March.(3)the ratio of total ash amount(290.34kg.ha^-1)to nitrogen amount(98.98kg穐a^-1)is 2.93:1, indicating the litterfalls of this forest belong to N-rich type.(4)the total amount of nine mineral elements in litterfalls is 128.5Sky.ha^-1, from maximum to minimum, their sequence is K>Ca>Mg>S>Mn>P>Fe>Zn>Cu.

Key words: biological soil crust, soil structure, water stability, moss-dominated crust, cyanobacteria- dominated crust