Provided are a method for dual-color imaging of sodium/calcium activities using a two-photon fluorescent probe and a method for preparing the two-photon fluorescent probe. The disclosed two-photon fluorescent probe for detecting calcium ions near the cell membrane reacts with calcium cations to exhibit strong two-photon fluorescence and may be selectively and easily loaded into the cell membrane by forming a complex with a calcium ion. Further, it allows imaging of the distribution of calcium cations in a living cell or tissue since it can selectively detect calcium ions in the living cell or tissue at a depth of 100 to 200 μm for more than 60 minutes. In addition, by staining the living cell or tissue with two probes of different fluorescent colors, the calcium and sodium activities can be imaged simultaneously at different channels.
