Abstract: AIM To investigate bioadhesion of carbopol and hydroxypropyl methylcellulose of different viscosity grade to rat gastrointestinal mucosa. METHODS The maximum adhesion force has been adopted as an index of adhesive evaluation in vitro, gastro-emptying rate and migrating length in intestine have been adopted as an index of adhesive evaluation in vivo. RESULTS In vitro adhesion studies indicated that the adhesive force of low-vicosity materials was stronger than that of high vicosity materials, while the transferation rate of high-vicosity materials is significantly higher compared to that of low-vicosity materials in vico. CONCLUSION Adhesive force of materials gives no correlation with rate of the materials in rat; Cb934 have the optium bioadhesion among the studied materials and can be used as the preferred adjuvant in oral bioadhesion preparation.