Abstract: Objective:An ultrasonic technology was employed to extract alkaloid from Selaginella involvens (ASI) .Furthermore, anti-proliferation activity on hepatocellular carcinoma cell H22 of mouse in vitro of ASI was observed.Methods:The alkaloids from Selaginella involvens were extracted by using ultrasonic-assisted ethanol.An orthogonal experiment was carried out to optimize the extraction technology.Furthermore, the proliferation inhibiting of hepatocellular carcinoma cell H22 was determined by MTT assay.Results:The optimum extraction conditions of polysaccharides was as follows:ethanol concentrations of 70%, solid-liquid ratio of 1:40, ultrasonic duration of 60min, ultrasonic power of 400W and ultrasonic temperature of 60℃.The highest alkaloid extraction rate reached 1.18%.H22 cell proliferation rate gradually increased with the alkaloid concentration and time increasing.Under the condition of alkaloid condensation of 8mg/mL, the growth inhibition was the highest after 48h and reached 53.25%.Conclusions:Ultrasonic method was a very effective method of extraction alkaloid from Selaginella involvens.The alkaloid could inhibit the growth of hepatocellular carcinoma cell H22 of mouse in vitro.