We study the photophysical characters of two oligofluorenes-functionalized anthracenes molecules with different fluorine-vinylene (FV) units, which exhibits that “excimer” state appears in the solution after photoexcitation. The dynamic data shows that two mechanisms are responsible for the generation of “excimer”. The fast one is controlled by the arene-arene interaction between molecules and the slow one is influenced by the diffusion motion of molecules. Increasing the number of FV units may suppress the DM-dependent “excimer” and enhance the yield of intrinsic fluorescence, which finally improves the fluorescence property of molecules in solution.