Moss crust is the top type of desertcrusts.The mossy crust layer also has a good effect on improving the ecologicalenvironment of the aeolian area and promoting the development of aeolian sandysoil.In thispaper，samples of mossy crustlayers under different sand fixation ages werecollected.The particlesize，humus characteristics and total chemical element content of the moss crusts layer were determined by conventional methods and inductively coupled plasma optical emissionspectrometry(PE ICP -OES).The results showed that the particle size of the mossy crust layer was mainly distributed in the range of 350～400μm，and with increasing sand -fixing age，<10 μm particle size of the particulate matter contentof mossy crust layer showed an increase trend.With increasing sand -fixing age，the organic matter content of mossy crustlayer increased from 8.61 g/kg to 11.95g/kg，total humid acid increased from 2.10 g/kg to 2.20g/kg，the humic acid contentincreased from 0.40 g/kg to 0.90 g/kg，and the optical properties of the absorbance of the humic acid E 4 and E6were increased， but the E4/E6ratio wasdecreased.The total chemicalcomposition(except SiO 2) of the moss crust layer was higher than that ofthe flowingsand，and with increasing sand -fixingage，the content of SiO 2in mossy crust layer showed a significant decreasetrend，but the content of other total chemical elements showed an increasingtrend.The rate of ferrosilicon in the moss crust layer waslower than that of the control flowingsand，with increasing sand -fixingage，the ferrosilicon ratio of mossy crust layer showeda decreasetrend.The content of total chemical elements and the ferrosilicon ratio in atmospheric dustfall were better thanthose of mossy crust and control flowingsand.The formation and long -term retention of the mossy crust layer in the aeolianenvironment could improve the content of fine particles，improve the characteristics of soil humus，increase the content ofmineralelements，and reduce the rate offerrosilicon，which had a positive effect on promoting the formation and evolution ofaeolian sandysoil.