Abstract: Taking the Daniudi Gasfield as an example，the genesis of the physical property of the tight sand stone reservoir is discussed in detail by comprehensively studying on these sedimentology，lithology and diageneses of the reservoir based on core，well logging，and chemical examination data.It showes that the distribution of microfacies decides the spatial distribution of reservoir property，while diageneses controls the reservoir space characteristics and capability in which compaction and cementation has damaging action on the preservation of original intergranular pore，and hence they reduce the porosity and permeability of the reservoir.While corrosion improves the physical property of the reservoir in certain extent and microcrevasse improves permeability of the reservoir and intensified the reservoir anisotropism.From the deposition，the rock，the diagenesis，physical property，choosing geology appraisal parameters，four kinds of reservoir are divided in the goal reservoir，in which prolific zoneⅠis mainly the river course granulated substance body compound belt that has the characteristics of low value GR curve，remarkably negative abnormal SP curve，thick detritus pellet，high quartz content，and remaining intergranular hole or intergranular dissolution pore.

Key words: Daniudi Gasfield, tight sandstone reservoir, classified characteristic, genesis, evaluation 