Abstract: OBJECTIVE To study the absorption characteristics of a nasal drug delivery of gardenia iridoid glycoside, so as to provide some technicial consults of its nasal drug delivery system. METHODS Using Franz diffusion cell, the fresh nasal mucosa of pig was used for permeability barrier, the geniposide was determined by HPLC as indexs. Using medicated PBS(pH=7.4) for nasal liquid circulation, the geniposide was determined by HPLC with using rat nasal circulatory perfusion experiments(in situ). RESULTS The apparent permeability coefficient (Papp) of geniposide was (2.01±0.23)×10^-5 cm^-2·s^-1, the steady state flow (Jss) of geniposide was (1.61±0.18)×10^-4 μg·cm^-2·s^-1, the diffusion through mucosa was a passive diffusion with concentration difference of both mucosal sides. The absorption kinetics equation of geniposide in rat nasal mucosa(in vivo) was lnC=1.165 7-0.001 6t, r=0.991 4, k=(1.6±0.021)×10^-3 min^-1. CONCLUSION Gardenia iridoid glycoside can be absorbed through nasal mucosa, which can be made into new nasal preparations for the prevention and treatment of brain diseases.