Abstract: The alkaloids in 20 cut tobacco samples were extracted with the mixture of 0.5% sodium hydroxide aqueous solution and ethanol(1:10,v/v) under ultrasonic for 30 minutes,separately.The extracts were filtered by 0.22 μm filter membrane,then the contents of cotinine,nornicotine,myosmine,anabasine and nicotine in the filtrate liquid were determined by UPLC with TUV at 259 nm.The results indicated that:1) the recoveries of the alkaloids were from 96.5% to 100.8% with RSD of 2.07% to 3.49% and the limits of detection of 6.33 to11.92 ng/g;2) the alkaloids in order of their concentrations in cut tobacco were nicotine>myosmine>nornicotine>cotinine>anabasine.