Phytochemical investigation of Corydalis decumbens has resulted in the isolation of one known Alkaloids named 1R,9S,7′S-O-methylegenine(1) and two new Alkaloids, 1S,9R,7′S-O-methyl egenine (2) and 1S,9S,7′S-O-methylegenine(3). Their structures were elucidated by various spectroscopic techniques. The absolute configurations of compounds 1–3 were determined by ECD calculations analysis.The anti-inflammatory activity of these compounds was evaluated in vitro with inhibition rates of release of β-glucuronidase from polymorphonuclear leukocytes of rats in the range of 32.4–41.3% at 10 μM and the results displayed that these compound showed potential anti-inflammatory activity and one of them is a promising compound for the development for new drug in the treatment for rheumatic arthritis. © 2016