There are well outcrop and full stratigraphic sequence of Nanhua System in Changyang area, Western Hubei province, mainly including Liantuo Formation, Nantuo Formation and small Gucheng Formation, Datangpo Formation (only in Gucheng area,Changyang county).The clastic rocks of Liantuo Formation formed in river or estuary environment,relatively thicker in South area than North area, vertical combination of lithology can be obviously divided into three sections. Gucheng Formation was typical glacial rocks, which corresponds to Sturtian glaciation. Datangpo Formation deposited in transitional facies during interglaciation. Nantuo Formation was the most developed and important moraine stratum, which corresponds to Marinoan Glaciation, little change in lithology and thicker in Southwest than Northeast. The value of CIA is varies between 52.52~55.80 in Nantuo Formation, indicates the rfigid -arid and low chemical weathering environment. The value of CIA is 68.14 at bottomn of Liantuo Formation, 61.61~64.57 in the lower part and 55.03～59.80 in the upper part, reflect the warm-damp and medium chemical weathering, the warm-arid and low chemical weathering, the rfigid- arid and low chemical weathering environment respectively. The value of SiO2/Al2O3 is varies between 2.13~5.10 in Liantuo Formation, Lower than the value of SiO2/Al2O3 (4.47~5.16 ) in Nantuo Formation. The value of FeO/Fe2O3 is varies between 0.16~0.49 in Liantuo Formation, Lower than the value of FeO/Fe2O3 (1.96~3.11) in Nantuo Formation. These differences demonstrates that the Nantuo Formation formed in frigid-arid and lower chemical weathering environment, but the Liantuo Formation formed in relatively warm and higher chemical weathering environment. These results show that the Nanhua System in study area experienced sedimentary environmental change,ie warm-humid or warm-dry and low-medium chemical weathering in interglaciation, to cold-dry and low chemical weathering in interglaciation, and to cold-dry and low chemical weathering in glaciation.