The dynamics of the excited-state proton-transfer reaction of 7-azaindole dimer has been investigated in hexane with use of the femtosecond fluorescence up-conversion method. Time-resolved measurements were performed in a wide fluorescence wavelength region from near-ultraviolet to visible (320-620 nm). Three fluorescence components due to the dimer were observed in addition to the fluorescence from coexisting monomer. Time-resolved fluorescence anisotropy measurements were also carried out, and the result indicated that the first (a = 0.2 ps) and the second (tau = 1.1 ps) fluorescence components due to the dimer arise from two different dimeric excited states having different transition moment directions. The decay of the second component agrees with the rise of the third component, which is attributable to the fluorescence from the tautomeric excited state (tau = 3.2 ns) formed by the proton-transfer reaction. The fluorescence spectra of these three excited states were reconstructed from time-resolved fluorescence traces taken at 27 wavelengths, and they show intensity maxima around 330, 350, and 490 nm, respectively. This sequential red shift reflects the cascaded population relaxation after the photoexcitation. By combining the spectral data with fluorescence quantum yield data, the oscillator strengths of the three excited states were evaluated as 0.13, 0.048, and 0.023. We assigned the higher- and the lower-energy dimeric excited states to the "L-1(b)" and "L-1(a)" states of the dimer on the basis of the obtained photochemical information. The deuterium substitution effects were also examined for two isotopic analogues. It was concluded that the proton transfer proceeds exclusively from the lowest "L-1(a)" excited state with a time constant of 1.1 ps, after the electronic relaxation takes place from the initially populated ("L-1(b)") state to the "L-1(a)" state. The excited-state reaction pathway as well as quantitative characterization of each excited state is discussed.