The tubers of Corydalis ternata have been used to treat cardiovascular diseases such as hypertension and cardiac arrhythmia. Its active components have anticholinesterase, antiamnesic, and anti-inflammatory activities, and analgesic effects. In the present study, we performed quantitative analyses of the two components of C. ternata , coptisine and berberine, using HPLC. A 70% ethanol extract of C. ternata was prepared and the two components were separated using a C-18 analytical column on a gradient solvent system of acetonitrile and 0.1% (v/v) aqueous trifluoroacetic acid. Recordings were performed at a UV wavelength of 265 nm for two standard components. The established analytical method showed high linearity (correlation coefficient ( r )=1.0000) and proper precision (0.49–3.88%), accuracy (97.88–102.7%), and recovery (95.12–103.79%) for two standard components. The amount of the coptisine and berberine was 4.968±0.089 mg/g and 3.73±0.075 mg/g, respectively. In addition, we investigated the effects of coptisine and berberine on acetylcholinesterase activity and amyloid-β aggregation, which are major biomarkers of dementia. Coptisine and berberine decreased acetylcholinesterase activity in a dose-dependent manner (IC₅₀=0.74 and 0.48 µM, respectively). The C. ternata extract exerted an antioxidant activity by stimulating the radical scavenging activity of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), but not 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, the C. ternata extract reversed the hydrogen peroxide-induced death of HT22 hippocampal cells, indicating its neuroprotective effect. Our results suggest the potential of C. ternata as a therapeutic agent against dementia via the inhibition of acetylcholinesterase activity and neuronal cell death.