Poly(amine-ester)-benzaldehyde dendrimer(PAE-BZA) was synthesized from ethyl enediamine (EDA), trimethylolpropane triacrylate (TMPTA) and benzaldehyde (BZA), the yield was 60.82%. The structure of PAE-BZA was characterized by IR、1H-NMR and 13C-NMR. The effects of different concentrations, different solvents and Sn2 on fluorescence properties of the dendrimer were studied. When acetone was solvent, fluorescence of 0.5mmol/L PAE-BZA was strongest. Take acetone, the methyl alcohol, DMSO, DMF and ethyl alcohol as solvent, fluorescence of PAE-BZA in ethyl alcohol was strongest. Fluorescence of PAE-BZA was first decreased then increased by Sn2 in the solution, and the complexing order of N atom was from periphery to internal.