Abstract: Objective: To establisha method used for quantitative detecting the neuronal gap junction function.Methods: The primary neurons were cultured,the purity of neurons was identified by immunofluorescence.Two kinds of different molecular weight of fluorescent dyes Calcein and Dil were incubated with neurons for 30 min to make donor neurons,and then incubated with received neurons for 2.5 h.The number of received neurons around the donor neurons was observed with inverted fluorescence microscope.Results: The purity of cultured primary neurons reached 90%,which could be used to defect neurons gap junction function.The received neurons around the donor neurons could be clearly observed and counted.Conclusions: The fluorescent tracer method established in this experiment can be used for quantitative detecting the neuronal gap junction function.