A fluorescent polymer F-PAM was prepared by the reverse microemulsion polymerization of Span80-Tween80/isooctane/FM［4-methoxy-N-(2-N′

N′-dimethylaminoethyl)naphthalimide allyl chloride quaternary ammonium salt］-AM(acrylamide)-H2O.The micro-structure，fluorescence property and size distribution of F-PAM particle were studied by using TEM，AFM，laser nanometer measurement and fluorescence spectrophotometer.The results showed that the polymer F-PAM was a mono-disperse，globular nanometer material，and the average diameter of PAM particles（D）was 60～145 nm.The wavelength of the excited and the emitted spectrum of F-PAM were 381 nm and 462 nm

respectively，and the shapes were symmetric as mirror images.Fluorescence intensity increased with the concentration of F-PAM，and the relationship of fluorescence intensity and concentration of F-PAM was linear.The correlation coefficient（R）was 0.9953.The lower limit of detection was 1.83 mg·L-1.