The laser induced breakdown spectrum characteristic of lead contained in lead slime is studied with a 1064 nm wavelength NdYAG laser as the exitation source, a echelle spectrometer of high resolution and wide spectral range for spectral seperation and a intensified charge coupled device for high sensitive detection. The characteristic spectrum line of PbⅠ405.78 nm is selected as the analytical line, the relationship of spectrum intensity and signal to noise ratio of PbⅠ405.78 nm varying with delay time and gate time are measured respectively. The optimum delay td=2.5 μs and gate tg=3.0 μs are confirmed. Under the approximation of local thermal equilibrium, 13 characteristic spectrum lines of Fe within the wavelength range of 360~441 nm are choosed, the temperature of plasma calculated by the means of Boltzmann diagram is 6934 K, and the electron density of plasma gained by using Lorentz fitting on PbⅠ405.78 nm is 8.3×1016 cm-3. These parameters provide a method and technical supports for fast quartitative analysis of lead sime.