The paper reports the establishment of a method for simultaneous determination of peimisine and sipeimine contents in Fritillaria walujewii Regel and Fritillaria pallidiflora Schrenk.  The analyses were performed on an ultra-performance liquid chromatography with evaporative light scattering detection (UPLC- ELSD), equipped with a binary solvent manager, a sampler manager and a column compartment, and connected to Waters Empower 2 software.  An Acquity UPLC^TM BEH C₁₈ column (100 mm × 2.1 mm, 1.7 μm) was used for all analysis.  The investigated compounds were separated with gradient mobile phase consisting of   acetonitrile-0.02% triethylamine-water.  The temperature of sample manager was set at 25 ℃.  Drift tube temperature was 40 ℃, and spray parameter was 40% with injection volume of 1 μL.  The investigated  compounds including peimisine and sipeimine had good linearity (r ≥ 0.9991) over the tested ranges.  The average recovery was 94.5% and 98.1% with RSD ≤ 2.36%.  The UPLC-ELSD method is simple, sensitive and accurate with good repeatability, which is available for quality control of F. walujewii Regel and  F. pallidiflora Schrenk.