Abstract: Laser induced breakdown spectroscopy (LIBS) was employed to investigate the soil. LIBS analyses were performed with Nd:YAG laser operating at 1 064 nm, 5.82 ns pulse duration. The spectral lines of Ca Ⅱ 393.37 nm and Ca Ⅱ 396.85 nm were selected as the analytical lines for optimizing the experimental parameters (ICCD delay, laser energy, ICCD gate width, repetition rate and cumulative number of spectrum) which had influence on spectral line. The experimental conditions were determined as follows. The ICCD delay was 1 s, the laser energy was 50 mJ, the ICCD gate width was 3.5 s, the repetition rate was 1 Hz and the cumulative number of spectrum was 100 times. Under the optimal experimental conditions, the results of the electron temperatures Te and electron densities Ne were 11 604 K and 5.1551016 cm-3, respectively. The local thermal equilibrium condition of the plasma was satisfied. The results are useful for the analysis and detection of elements in soil.