An on-line Ag/Al galvanic cell is investigated and employed to generateelectrochemiluminescence (ECL). The potential of the galvanic cell could be adjusted by varyingthe components of flow reagent. The cell performed perfect capability of supplying a stablepotential for ECL generation. Based on the weak ECL ofcalcein blue could be greatly sensitizedby the presence of calcium in alkaline solution, calcium contents in milk samples and in cabbagewere assayed and the results were compared with those from ICP-AES method.