Objectives: Paleosedimentary environmental study of mud—shale member of Cretaceous Madongshan Formation(Fm. ) in the Liupanshan Basin includes the paleoclimate, paleosalinity, paleoredox conditions and paleobathymetric through 10 samples collected from well Gucan1 in the basin. Methods: Based on geochemical element analysis and a series of identification indexes of paleoclimate, paleosalinity, paleoredox conditions and paleobathymetric，such as CaO/(MgO·Al2O3), Sr/Cu, Rb/Sr, Sr /Ba, Sr abundance, Th/U, V/Cr, V/(V+Ni), Fe/Mn and (Al＋Fe)/(Ca＋Mg) to restored its Paleosedimentary environmental. Results: Comprehensive analysis shown that the sedimentary period of mud—shale member in the Madongshan Fm. , the paleoclimate was warm temperate higher than 15 ℃，the water body was brackish—salt water of semideep to shallow lake, and the sediments were deposited under strong reduction conditions. The paleoclimate, paleosalinity, paleoredox conditions and paleobathymetric had 3 relative changes cycles in vertical direction, and the paleoclimate had a positive correlation with paleoredox conditions and paleobathymetric while had a negative correlation with paleosalinity. Conclusions: Paleoenvironmets factors of relative changes of 3 cycles such as appropriate paleodepth, strong reduction conditions, stable and scarce supply debris jointly control the heterogeneous of unconventional shale and gas reservoir facies of the Madongshan Fm.