Two-photon dyes for real-time imaging of lipid rafts are provided. The two-photon dyes emit fluorescence with high intensity in the environments of cell membranes and can be used to clearly discriminate the hydrophobic and hydrophilic domains of the cell membranes. Therefore, the use of the two-photon dyes enables satisfactory imaging of actual lipid raft domains. In addition, since the two-photon dyes show no cytotoxicity, they can be suitably used in bioimaging applications, for example, real-time imaging of lipid rafts over a long period of time.