Abstract: In order to investigate the nicotine permeation behavior in oral mucosa from snus, a device was designed which incorporated a matching skin permeation diffusion cell and a pig's oral mucosa. The effects of pressure, pH and moisture content on the nicotine permeation rate from snus were studied by combining the designed device with high performance liquid chromatography. The results showed that: 1) R² of the standard curve of nicotine concentration was 1.000 in the range of 0.70-44.65 μg/mL and the recovery ranged from 96.45% to 98.96%. 2) Nicotine permeation from snus through the pig's oral mucosa as time presented a linear relationship, which belonged to a mucosa film-storage type. 3) Within 0.5-12.0 h, applying a pressure of 6.65× 10^-2 N/cm² significantly increased the permeation rate of nicotine. 4) When the moisture content of the snus sample was between 30% and 50%, the permeation rate of nicotine from snus at pH of 7.4-8.4 was significantly higher than that at pH of 5.3-5.4. Therefore, the nicotine permeation behavior of snus in oral mucosa could be regulated by changing the pressure and pH of snus.