Abstract: The invention feature series of benzothiazole derivatives as potent immunosuppressive and antiinflammatory agents. Eight compounds 2, 4, 5, 8, 9, 10, 12, and 18 showed potent inhibitory activity on PHA-activated T-cell proliferation. Compounds 2, 4, 8, and 18 were found to have a potent inhibitory activity with IC50 values ranging <1.0-2.9 ?g/mL against IL-2. Studies on innate immune response revealed that compounds 2, 8, 9, and 10 have significant suppressive effect on ROS production with an IC50 values 1.9, <1, 3.7 and 1.1 ?g/mL, respectively. The LPS-induced nitrites in J774 macrophages cell line was inhibited by 4, 8, 9, and 18 at a concentration of 25 ?g/mL (56-91%). In addition compounds 5, 8, 12, and 18 showed potent suppression on interleukin 4 (IL-4), particularly 9 (IC50<1 ?g/mL). No cytotoxicity was found except for compound 9 and 18 (11.4 and 10.4 ?g/mL IC50), respectively.