LWD resistivity data are mainly used in horizontal well logging interpretation. Compared to vertical well, the responses of electrical logging in horizontal well seem to be more complicated. It not only needs to consider bed thickness and shoulder bed, but also should take borehole inclination and formation resistivity anisotropy into account. Different formation models were established for numerical simulations to analyze the responses of the ARC675 resisitivity tool to the environmental factors, including bed thickness, shoulder bed and resistivity anisotropy. A field log example is used to support the calculations presented. The method is not only used to determine the geometry relationship of well trajectory and formations precisely, but also to interpret the reason why there are large differences between the responses of phase shift resistivities and attenuation resistivities which are both highly different to the resistivities of pilot well. The results of this study can be used to guide the determination of fracturing in field application.