Abstract: The emulsified asphalt products have many disadvantages when being used as shale inhibitors for drilling fluid, such as high colloid content, poor stability, serious pollution, poor dispersion and poor anti-collapse. In this work, a C9 petroleum resin and an aromatic oil were used as the main blending raw materials. The preparation procedure is similar to the conventional preparation method of asphaltic-type shale stabilizer. After the sequential steps of blending, emulsification and stabilization, a new type petroleum resin shale inhibitor (PRSI) was obtained. Results showed that PRSI could inhibit shale swelling, dispersion, and reduce the filtration loss. In addition, PRSI had good compatibility with other additives and did not affect the rheological properties of drilling fluid. When the mass fraction of PRSI was 2%, the water loss of drilling fluid decreased by 18%, and the relative reduction rate of core expansion was 7.4% higher than that of the emulsified asphalt. As a shale stabilizer, it has a good application prospect in oil and gas drilling.