Naphthalimide and coumarin were bonded together with -NHN= being as the linkage. The emission behavior was investigated in various solvents. The energy transfer is independent in weak and medium polarity solvents. Efficient energy transfer occurred with the emission of it in polar solvent. In addition, it is highly emissive in polycarbonate and the energy transfer from coumarin to naphthalimide is more efficient. Another significant feature is its selective F- response. Upon the F- addition, the absorption around 444nm shifted to 486nm. And the new absorption band decreased and another new absorption band appeared around 574 nm.