In this paper, the color reaction of copper with trimethoxyphenylfluorone (TM-PF) in microemulsion has been studied. Copper (II) reacts with TM-PF to form a stable 1:2 complex at pH 10.40. Its apparent molar absorptivity is 1.46 x 10(5) L x mol(-1) x cm(-1) at 552 nm. Beer's law is obeyed in the range of 0-0.6 microg x mL(-1). Sulphydryl dextran gel (SDG), in which sulphydryl group has a big share, is a new type of metallic ion adsorbent. It presents the advantage of higher adsorption capacity, better reuse ability and higher mechanical stability. So the coexistent metal ions can be separated effectively and copper can be enriched by SDG, greatly improving the selectivity and sensibility of the system. The method was used to determine trace amount of copper in blood, urine, iron ore and water samples with satisfactory results, the relative standard deviation is less than 4.8%, and the recovery is 94.2%-106%.