Abstract: The release characteristics of ammonium glycyrrhizinate from the W/O/W type multiple emulsion,the simple aqueous solution and the muItiple emulsion of drug contained in theouter aqueous phase was studied by dialysis method,A linear relationship was observed between thepercentage of drug released and the square root of time,The release of ammonium glycyrrhizinatefrom the W/O/W type multiple emulsion was slower than that from the aqueous solution. When drugwaS contained not in the inner aqueous phase but in the outer aqueous phase,the relcase pattern ofammonium glycyrrhizinate was similar to that from the simple aqueous solution,These resuIts suggestthat this preparation has the notable effect of sustained release and the release of drug transport throughthe oil phase still holds Higuchi pattern.