Abstract: This paper presents the characteristics of the low resistivity hydrocarbon zones and the core experimental study results in Jiling oilfield. Additional conductivity of clay and well-developed secondary pores are believed to be the main causes of the low resistivity hydrocarbon zones. Reservoirs with well-developed secondary pores display low resistivity features when they contain hydrocarbon. The occurrence of clay minerals further lowers the resistivity of hydrocarbon zones. The Waxman-Smits model for muddy sandstone is applicable to clay-bearing low resistivity hydrocarbon zones.