Laser-induced breakdown spectroscopy (LIBS) technique has a powerful application in elements detection,so it has become a popular object for scholar s.In this article,the Na content of milk samples is detec ted using LIBS.A total of 15milk samples are analyzed,of which 9known samples are used as the calibration sam ples,and a regression model for quantitative analysis of Na is established by using the method of partial least squares (PLS);other 6samples are used as the test samples to verify the results of quantitative analysis by the model .The LIBS is used to detect the Na content in 6test samples,and the linear correlation coefficient between reference cont ent and predicted content is 0.9938with the relative error less than 15%.LIBS technology can rapidly and accurately measure the Na con tent in the milk,which indicates a great application potential.