Abstract: A large number of zeolite cements have been found in the reservoirs of the lower Wuerhe formation in the slope area of Mahu sag, Junggar basin. In order to clarify the influences of zeolite minerals on reservoir quality and oil-bearing property, the experimental methods such as rock thin section, casting thin section, SEM, energy spectrum, electron probe, cathodoluminescence, whole-rock diffraction and inclusions have been used to research the characteristics, types and distribution of zeolite minerals. Furthermore, the formation mechanism of zeolite minerals in reservoirs is clarified and the relationship between the development of zeolite and oil-bearing property of reservoirs is revealed. The results show that five kinds of zeolite minerals are developed in the reservoirs of the lower Wuerhe formation in the slope area of Mahu sag. The zeolites are mainly consisted of laumontite with small amounts of heulandite and trace amounts of analcime, clinoptilolite and stilbite. The heulandite commonly coexists with laumontite and small amounts of clinoptilolite coexists with heulandite. The distribution of zeolites is controlled by sedimentary facies, the laumontite is mainly developed in the fan delta front with relatively good porosity and permeability and the heulandite is developed in the front of fan delta plain. The genesis of zeolite minerals can be divided into three types of two categories, namely metasomatic genesis model caused by plagioclase albitization and volcanic material alteration and cementation genesis model which is the dominant. The precipitation of zeolite in the early stage of diagenesis enhanced the ability of reservoir to resist normal compaction so that partial primary pores could be preserved, which provided flow channels for acid fluid and dissolution in the middle stage of diagenesis. The dissolution of zeolite during hydrocarbon accumulation period is beneficial to the high quality reservoir formation