A 6′,8′-di-tert-butyl-1-hydroxyethyl-3,3-dimethyl-indoline benzospiropyran L1and its derivative L2 were synthesized and characterized. Chelation-enhanced appearswhen L1 with electron donating groups of 6′,8′-di-tert-butyl touch on benzospiro--pyran and affect the stability of cyanine structure. L1 exhibited high selectivity to Hg2+, Cr3+, Ag+ over other metal ions. While, there was no obvious interferences of coexist metal ions on Hg2+, Cr3+, Ag+ detection. The Hg2+, Cr3+, Ag+ recognition of L1 not only could be achieved by means of fluorescense and absorption “turn-on” spectra but also an obvious color change from colorless to yellowish by naked-eyes. The binding of L1 to Ag+, Cr3+, Hg2+ are in 1∶1 stoichometry and the detection limits are 7.435 8×10-6, 6.126 8×10-6, 3.452 4×10-6 mol·L-1. The sensing mechanism was also investigated from L2.