Genesis of low-resistivity oil layers from cretaceous system in Luxi area was studied. The result shows that the resistivity of oil layers is lower than that of water layers from Tugulu Group(K1tg),Cretaceous in Luliang area,Zhungeer basin, resulting in a disaccordance with logging interpretation on oil layers,oil-water layers and water layers.The research on the petro-texture of reservoirs also shows that the watered clay pellicle (I/S, I, ch) is well developed in K1tg expands the section of conductive net and results in a low resistivity of oil layers.