Cirsium japonicum DC (Asteraceae) is a perennial thistle widely distributed in Asia, it is also consumed as functional food and herb in China. To analyze the health effects of C. japonicum, flavonoids, saponins, polysaccharides, essential oil, coumarin and alkaloids were extracted from C. japonicum, and their cytotoxicity to normal cells, anti-inflammatory effect against LPS-induced RAW 264.7 macrophages, antiproliferative effects against human lung adenocarcinoma cell A549 and anti-atherosclerosis activities in ox-LDL-stimulated RAW 264.7 cell were investigated. Results showed that coumarins exhibited strongest cell toxicity (IC50 = 162.7 mu g/ml), and alkaloids showed slightly cytotoxicity at high concentration. Saponin could significantly inhibit cancer cell proliferation, especially for A549 cell and the inhibition rate reached to 47.0% at concentration of 200 mu g/ ml, which might result from the promotion of ROS generation in cancer cell. Saponin, essential oil and flavonoids could dose-dependently inhibit NO production in LPS-induced RAW 264.7 macrophages, whose inhibition rates were 65.4%, 73.0% and 80.4% at concentration of 50 mu g/ml, respectively. Besides, saponin, essential oil and flavonoids also decreased lipid accumulation in ox-LDL-induced RAW 264.7 cell, which might be beneficial for cardiovascular health. These results indicated that different components from C. japonicum exhibited different bioactivities, providing useful information to better use thistle resources.