Abstract: The shales in the Permian Dalong Formation in the northeastern Sichuan Basin represent typical high-quality marine reservoirs with substantial potential for shale gas exploration and development. However, systematic experimental studies on their rock physical properties remain insufficient, resulting in a lack of solid petrophysical basis for sweet-spot prediction. To address this, our study focuses on the systematic lab testing and analysis of the petrological, reservoir, and rock physical characteristics of the shale samples from the study area. By integrating with the microstructural observations and incorporating a multi-porosity hypothesis, a rock physical model, and corresponding interpretation templates, is established based on the self-consistent approximation and differential effective medium model. The results indicate that Dalong shales mainly comprise siliceous, mixed, and calcareous shales. The mineral composition is characterized by high silica content, high carbonate content, and low clay content. The rock physical responses present high porosity, high total organic carbon (TOC) content, low wave velocity, and weak anisotropy. The model-based calculations show high consistency with core data. The model-based shear velocity predictions demonstrate an 85% match with measured log data, providing a reliable theoretical foundation and technical support for seismic sweet-spot prediction in Permian Dalong shales in northeastern Sichuan Basin.