Abstract: OBJECTIVE A method for simultaneous determination of 16 chemical components in aqueous extract of Sinisan was established. METHODS UHPLC-QqQ-MS technology was employed. Scan was conducted in negative ion mode and quantitative determination was carried out by MRM paired ions. RESULTS Saikosaponina A， saikosaponina B₂， saikosaponina C， saikosaponina D， hesperitin， cianidanol， liquiritin， glycyrrhizic acid， liquiritigenin， chlorogenic acid， gallic acid， paeoniflorin， albiflorin， isoliquiritigenin， isochlorogenic acid A， and hesperidin all have good responses in negative ion mode. CONCLUSION The established method is specific， rapid， sensitive， accurate， and reliable， which can simultaneously determine contents and accurately give mass information of compound to achieve the effects of component identification， and also it can provide references for quality control and evaluation of aqueous extract of Sinisan.