The strip has anti-Cal coating antibody on test region, which is fastened to membrane chromatography in advance. Lable pad is coated by fluorescence labeled anti-Cal antibody in advance. When testing positive sample, the Cal in sample can be mixed with fluorescence labeled anti-Cal antibody, and form immune mixture. As the mixture is allowed to migrate along the test strip, the Cal conjugate complex is captured by anti-Cal coating antibody on the membrane and forms complex. The fluorescence intensity is positively correlated with the Cal content. The Cal in sample can be detected by fluorescence immunoassay analyzer.