Abstract: A new method for separation and determination of four important tropane alkaloids (hyoscyamine, scopolamine, anisodamine and anisodine ) in crude drugs by micellar HPLC was developed.The mobile phase was optimized with the modified simplex method (MSM). The chromatographic response function (CRF) was used as the criterion of optimization and three dimension simplex was used in this course. After eight tests, the given accuracy was achieved. In the optimized system the four tropane alkaloids are separated not only from each other but also from the interfering components in the crude drugs. The CMC of SDS in mobile phase was determined to be 5 mmol/L by circle method. The experimental evidences show that the optimized system is micellar chromatography.This method is simple, sensitive and accurate. The extraction solution can be injected directly without the need of a general purification procedure. Several plant materials containing tropane alkaloids were determined. The results and chromatograms are reported in this paper.