The electrical properties of rocks represent a significant area of research within disciplines such as reservoir geology and petrophysics. In particular, the characteristics of complex resistivity in unconventional reservoirs can yield valuable insights and methodologies. The dispersion behavior of rock electrical parameters is intricately linked to factors including mineral composition, pore structure, and fluid occurrence states. A comprehensive understanding of the electrical dispersion in shale and its influencing factors is essential for advancing shale petrophysics and characterizing shale reservoirs. To explore the impact of petrophysical parameters on electrical dispersion in shale, we conducted complex resistivity experiments on 13 shale samples exhibiting diverse physical properties and saturation conditions. Our analysis revealed that with increasing frequency, both the amplitude and real component of complex resistivity decrease; conversely, the phase angle and imaginary component initially decline before rising again to reach minimum values. Notably, the frequency dispersion observed in the imaginary part and phase angle surpasses that seen in both modulus and real components of complex resistivity, thereby providing a more accurate reflection of reservoir physical property parameters. We introduced a frequency dispersion parameter (D) to quantify this phenomenon effectively. The results indicated linear correlations between both phase angle and imaginary component with water saturation, porosity, and permeability metrics. Furthermore, quadratic or linear relationships were identified between Total Organic Carbon (TOC), specific surface area, and shale dispersion characteristics. This study presents novel methods and insights for predicting key parameters such as porosity, permeability, and water saturation within shale reservoirs-contributing significantly to geological evaluations.