We quantitatively analyze the content of element Cr in the national standard soil samples by the method of plasma atomic emission spectroscopy, through using Nd:YAG (Wavelength:1064 nm) laser as an excitation source to induce soil plasma in ambient environment of the laboratory. The calibration curve of element Cr is measured by studying the characteristics of laser-induced breakdown spectroscopy of element Cr in soil under optimal conditions. The experimental results demonstrate that the element content (60—400)×10-6 and the spectral line intensity are in good linear relation, and the relative standard deviation of element analysis of concentration measurement from the standard value is 7.89%. The relative deviation of the quantitative analytic result from the standard value is 5.3%, and the detection limit of Cr in soil is 16.3×10-6. The relative deviation by the internal standard method is 2.7%, which indicates that the internal standard method can improve the accuracy of the measurement. Using the same type of soil to achieve the calibration curves, the relative deviation by the quantitative analysis is 8%.