Obvious dolomite deposition during the Holocene was found by using X-ray diffraction analysis in Lake Huahai,Hexi Corridor.The dolomite deposition was in deoxidizing environment during the Holocene according to the lithology,sediments characteristics, gypsum and the changes of Fe³⁺.It provided new evidence for the research of dolomite formation.Dolomite,as a kind of carbonate mineral,can indicate the lake water salinity.However,it can not indicate the salinity increase directly.The decrease of dolomite content is corresponded with the increase of salinity in sulfate lake.Dolomite and gypsum changes in Lake Huahai can be used to reconstruct lake salinity during the Holocene.During 10.47 8.87 cal ka B.P.,lake salinity was high,implying the climate change from arid to humid.During 8.87 cal ka B.P.,a mount of gypsum deposition revealed increase in water salinity and arid climate.After that,water salinity decreased and the climate was humid.After 5.50 cal ka B.P.,hiatus indicated arid climate.