In order to enhance the ability of laser-induced breakdown spectroscopy to detect low content composition,the enhancement effect of Ar atmosphere at high-pressure(0.0-0.5 MPa) on the emission spectrum of steel sample was studied.The sample is ablated by a neodymium glass high-energy pulse laser(～6 J).The plasma spectrum was recorded by a multi-function grating spectrometer and a CCD spectral collecting-processing system.The plasma electronic temperature was calculated by the measured line intens...