Qualitative analysis and quantitative detection on the content of copper in the lake are implemented by laser induced breakdown spectroscopy. In the experiment, the spectral intensity value of Cu at 324.75 nm is measured in the concentration of 2~75 mg/L with laser energy of 120 mJ, delay time of 1.28 μs and repetition frequency of 1 Hz. Qualitative analysis is carried out on the characteristic spectral line of Cu, and the calibration curve of Cu about the concentration and spectral intensity, with the correlation coefficient R2=0.99, is obtained. The detection limit of Cu is 7.37 mg/L through the detection limit formula. In the end, the content of Cu in the lake is detected using the calibration curve and the result is 10 mg/L. The experiment proves that the heavy mental of Cu in water solution can be quickly detected by LIBS.