The ultrafast photophysical properties of dimethyl amino styryl pyridine acetonitrile (DASPA) were studied by the femtosecond transient absorption spectra (TA). The results show no evidence of state-to-state relaxation. The excited energy is released by the interaction between DASPA and solvent molecules. The solvation relaxation in protic solutions is faster than that in aprotic solutions, which results in a rapid decay of fluorescence. An energy diagram is finally proposed to interpret the relaxation mechanism.