Abstract: Carboniferous low resistivity oil layers in Tahe oilfield are under the control of structural trap and lithologic trap with low amplitude in the Ordovician top surface uplift.As the reservoir resistivity and the water layer resistivity value are so close,it is difficult to correctly identify them.In order to solve this problem,based on core analysis,slice observation,formation water analysis and mercury injection data,the genetic analysis of the carboniferous reservoir in Tahe oilfield low resistance has been carried out.The results show that high formation water salinity and high irreducible water saturation are the main causes of the low resistance oil layers.Therefore,the logging parameters interpretation model suitable for this area has been established.According to the logging parameters interpretation result,testing and logging data and by use of intersection diagrams,the identification standard for oil and water layer has been established.This standard can be applied to practical work and has achieved good results.