采用超高效液相色谱法测定羊栖菜中岩藻甾醇的含量。羊栖菜试样（2.000 0 g）经甲醇-二氯甲烷（1+1）混合液提取，所得提取液以YMC-Pack ODS-A色谱柱为分离柱，以甲醇-乙腈（3+7）混合液为流动相，在检测波长210 nm处进行测定。岩藻甾醇的质量浓度在0.5~400 mg·L^-1内与其对应的峰面积呈线性关系，检出限（3S/N）为0.16 mg·L^-1。在25，50，100 mg·L^-1等3个浓度水平进行加标回收试验，回收率在91.2%~96.8%之间。测定值的日内及日间相对标准偏差（n=6）分别在1.1%~5.4%，2.8%~7.0%之间。

UHPLC was applied to the determination of fucosterol in Sargassum fusiforme. The Sargassum fusiforme sample (2.000 0 g) was extracted with mixed solution of methanol and dichloromethane (1+1). In the HPLC separation YMC-Pack ODS-A chromatographic column was used as stationary phase, and a mixture of methanol and acetonitrile (3+7) was used as mobile phase. UV-detection at 210 nm was adopted in the determination. Linear relationship between values of peak area and mass concentration of fucosterol was kept in the range of 0.5-400 mg·L^-1 with detection limit (3S/N) of 0.16 mg·L^-1. Tests for recovery were made by standard addition method at the concentration levels of 25, 50, 100 mg·L^-1, giving values of recovery in the range of 91.2%-96.8%. Values of intra-day an inter-day RSD's (n=6) found were in the ranges of 1.1%-5.4%, and 2.8%-7.0% respectively.