Abstract: The strata of Late Palaeozoic in Linqing depression are an important exploration horizon of Shengli oilfield.Studies on the reservoir of coal-formed gas will play an important role in oil-gas resources exploration and the replacement of energy.This paper has taken the sedimentology, petrology and stratigraphy as the main research means.Having summarized the sedimentary systems and sedimentary facies of Late Palaeozoic, the paper analysed the physical characteristics of the sandstone reservoir in Shanxi Formation, Shihezi Formation and so on.Study showed that there are four sedimentary systems, that is, the tidal flat sedimentary system, the barrier-lagoon sedimentary system, the river-controlling shallow water delta sedimentary system and the river-lake compound sedimentary system.Among which, the distributary channel sand body of delta, the sedimentary sand body in the large river, lake and lake-delta are the favorable reservoir of coal-formed gas.The main rock types of the reservoir are the feldspar sandstone, quartz sandstone, lithic sandstone and the hard sandstone.The quartz sandstones are quite developed in Kuishan section, and the feldspar-quartz sandstones are quite developed in Shanxi formation.