AIM:To make compound demethycantharidin(including Radix astragali and Rhizoma bletillae) into stomach remaining-floating sustained-release preparation. METHODS:Radix astragal and Rhizoma betillae pulverized to superfine powders were combined with hydrophilic gel to manufacture stomach remaining-floating sustained-release tablet(floating tablet). RESULTS:The tablet started to drift in 3 min in the artificial gastric juice and float lasted for more than 8 h. By isotopic tracering,the floating tablets given on an empty stomach were retarded for 2-3 h and on large meal for 4-5 h in combination with ordinary tablet only retarded for 1 h. A pharmacopoeia dissolution method was set up to determine the release. 50% of tablets were disintegration in 5 h,70% in 8 h. The t 1/2 was 5.1 h(2-4 h for ordinary tablets),and the MRT was 8.3 h(3.3 h for ordinary tablets),and the remaining-floating sustained-release tablets showed a relative bioavailability of 230.71%. CONCLUSION:Pretreatment of raw herbs from compound demethylcantharidin and selection of the excipients will help to produce the herb-containing floating tablet.