Three new 8-aminoquinoline-5-azo derivatives: 5-(3-fluo-4-chlorophenylazo)-8-aminoquinoline (FCPAQ), 5-(3-fluo–4-chlorophenylazo)-8-benzenesulfonamidoquinoline (FCPBSQ), 4, 4'-bis (8-aminoquinoline-5-azo)-biphenyl (BAQABP) have been synthesized, and were found to be good fluorescence reagents for the determination of copper (II). In slightly acidic or basic medium, copper (II) reacts with FCPAQ, FCPBSQ or BAQABP to form a chelate, which exhibits an intensive fluorescence in ultraviolet region. The fluorescence intensity is proportional to the concentration of copper (II) over the range of 4.0-140, 1.0-200 and 3.0-150μg 1-1 with the detection limits of 0.80, 0.20 and 0.50μg 1-1 for the FCPAQ, FCPBSQ and BAQABP systems, respectively. The methods have been successfully applied to the determination of trace amount of copper in ore, alloy, water and hair samples.