Objective To optimize the extraction technology of Herba Swertia Davidi. Methods The extraction technology was optimized by orthogonal design L9(34), while Swertiamarin was adopted as the index. Factors such as extraction time, ethanol quantity and immersion were evaluated to determine their effect on the extraction process. Results The optimum extraction condition was soaking in 10 and 8 times of 50% ethanol for 0.5 h; the extraction times was 1.5 and 1.0 h. Conclu- sion The extraction procedure is reliable and simple, which provi...