Abstract: AimTo synthesize a series of 2-arylimino-4-thiazolidone derivatives and 2-imidazolino［2,3-b］-4-thiazolidone in order to get some novel potent compounds with nitric oxide synthases (NOS) inhibitory activity. MethodsThe target compounds were prepared by reaction ofN-chloroacetyl-1,2,3,4-tetrahydroisoquinoline orN-chloroacetylphthalimide with substituted thioureas, their NOS inhibitory activity were measured. Results and ConclusionThe 15 new compounds were synthesized and most of the reaction yields were over 65%. The structures of new compounds were identified by IR, 1H NMR, MS and elemental analyses. Bioassay indicated that, most of 15 new compounds synthesized had confirmed bioactivities inhibition against NOS.