Statistical data of the oil-gas filling degree of the lithological oil-gas reservoirs (the ratio of the volume of the sand body filled by oil and/or gas to the volume of lithological oil-gas reservoir) in the Jiyang depression show the following two facts. (1) Oil-gas filling degrees of the lithological oil-gas reservoirs and their distribution characteristics are different in different sags. The oil-gas filling degree is between 6.8% and 94.1% with an average of 46.5% in the Dongying sag, between 7.4% and 78% with an average of 46.6% for the Zhanhua sag, and between 5% and 60% with the average being only 19% for the Chezheng sag. The lithological oil-gas reservoirs are mainly distributed in the third and second members of the Shahejie Formation and the average filling degree of the third member is higher than that of the second member. In addition, the filling degrees of the lithological oil-gas reservoirs are different in different structure zones and different sedimentary systems. (2) Oil-gas filling degrees of the lithological oil-gas reservoirs and their distribution characteristics are different in different types of lithological oil-gas reservoirs. The oil-gas filling degrees of the overwhelming majority of the isolated sand bodies are over 40%, which are generally larger than those of the sand bodies connected on the flanks of the faults.