The fluorescence lifetime of anthracence in three different states (solution

crystal

thin film) have been systematically measured by means of single-photon counting technique. Because there are a few disadvantagous factors: 1) finite time width of the excitation source; 2) transit time divergency of photomultiplier; 3) finite response time of electronic systems. These factors have been removed by deconvolution method and then accurate lifetime values have been obtained. We have got following conclusions: i) the lifetime of anthracence in benzene and ethanol shorten with increase of the concentration (Table 1) and they are approximately the same for different emission peaks in the solutions; ii) the lifetimes of anthracence in the solids are longer than that in the solutions. (τ=15.3ns for the crystal

τ=19.lns for the thin film).The excitation

emission spectra have been measured in the different states. It is observed that there are widening of emission bands and red shift of emission peaks in the solids. There are greater change for the excitation spectra and much smaller for the emission spectra with the increase of the concentration.It is considered that the lifetimes shortened with the increase of the concentration come from concentration quenching. The obvious change for the excitation spectra in different concentration may be originated from the interaction between different condensed anthracence molecule states.