Quantitative reconstruction of paleoclimate is the key to the research on fine-grained sediments. To solve this problem，three factors that can reflect the paleoclimate were proposed，which are moisture index，terrigenous clastic and carbonate. Based on these factors，the paleoclimate indicator was extracted by SPSS，and a method for paleoclimate quantitative reconstruction was established. The larger the value of paleoclimate indicator，the more humid the paleoclimate. To a certain extent，this method overcomes the limitations in paleoclimate reconstruction using single method and keeps the relevant information of the selected factors to reflect the paleoclimate，and thus the reconstruction result is more reasonable and more practical. Using the established method，the paleoclimate was reconstructed based on data of Wells Fanye1 and Niuye1 in Dongying Sag during deposition of the upper Es4 and the lower Es3. Meanwhile，the effect of the paleoclimate on fine-grained sediments was studied from three aspects，including organic matter abundance，sedimentary structure and lithofacies. The results show that there are four paleoclimatic cycles during the deposition of the upper Es4 and the lower Es3 in Dongying Sag，which are arid to semi-arid，semi-humid to humid，semi-arid and semi-arid to semi-humid. The paleoclimate changed gradually from arid to humid. As a result，a fine-grained sedimentary lithofacies evolution sequence developed vertically，which are organic-rich laminated limestone lithofacies，organic-rich laminated argillaceous dolomite lithofacies，organic-rich layered argillaceous dolomite lithofacies，organic-rich laminated argillaceous limestone lithofacies，organic-rich laminated lime mudstone lithofacies，organic-rich layered argillaceous limestone lithofacies and organic-rich layered lime mudstone lithofacies.