The Chafangcun profile in Danfeng,Shaanxi,China were surveyed in detail and then sampled systematically. The stratigraphic and sediment logical characteristics,chemical weathering intensity and the profile structure were observed in the field.Magnetic susceptibility,particle-size distribution,geochemical characteristics were analyzed in laboratory.Results are shown as follows:(1) The stratigraphic sequences of Chafangcun profile changed with the stratigraphic series MS-L_0-S_0-L_t-L_1.(2) The major elements such as Ca,Na,Mg,K and Si were migrated and leached,while the element Fe was slightly enriched during the chemical weathering process.According to the migration ability,the major elements were ranked in the following order:Na>Si>Mg>K>Ca>Al>Fe.(3) The Chafangcun loess have finished the primary chemical weathering process and almost reached the secondary process as a whole.The aeolian sediments went through different degree of pedogenic modification in different periods with the sequence S_0>L_t>L_1>L_0.Geochemical characteristics of major elements indicate that the climate changed as"cool-dry (before 11500 a BP) cool-wet(11 500~8 500 a BP) warm-wet(8 5003 100 a BP) cool-dry(since 3100 a BP) ".