By investigating of the optical properties of the first generation π-conjugate unsymmetrical dendrimer with anthracene core (PD-G1), we found that compared to the G-OH, the increasing of the conjugate length resulted in the improvement of the range and intensity of the absorption and fluorescence emission spectra, and shows an energy funnel effect from the outside branches to the anthracene core. Fluorescence quenching phenomenon via the formation of ion pairs with the electron-defect compounds nitrobenzene, 2,4,6-trinitrotoluene (TNT), and electron-sufficient compound p-dimethoxy benzene indicated that the PD-G1 can act as either electron acceptor or donor, and the quenching constant were 144, 557 and 169 L/mol, respectively. The quenching efficiency of TNT to PD-G1 can reach 74%. Hence the PD-G1 shows potentially application in light harvesting, emission and fluorescent sensor material.