The invention discloses a method and a device for determining the
water saturation of a stratum, and belongs to the field of
oil well logging technologies. The method includes selecting series representative cores of a measured region, and measuring values of porosities POR of the series cores and values of
specific resistance R<w> of saturated stratum water of the cores; creating a
functional relation m(POR, R<w>) among bond indexes m of the cores, the porosities POR of the cores and the
specific resistance R<w> of the stratum water; creating a
functional relation n(R<w>, POR) among saturation indexes n, the porosities POR of the cores and the
specific resistance R<w> of the stratum water; solving the
water saturation S<w> of the stratum by the aid of an Archie
water saturation interpretation model. The device comprises a selecting module, a parameter measuring module, a bond index creating module, a
saturation index creating module and a saturation computing module. The method and the device have the advantages that the functional relations among values of the bond indexes m, values of the saturation indexes n, the porosities POR and the specific resistance R<w> of the stratum water are created, so that the values of the bond indexes m, the values of the saturation indexes n, the porosities POR and the specific resistance R<w> of the stratum water are relevant to one another, and the computed water saturation of the stratum is accurate and reliable.