Measuring soil carbon is essential for accurately estimating carbon inventories and changes in different landscapes and ecosystems. Current measurement technologies for soil C require extensive time for processing and analysis. Developing more efficient methods of measuring soil carbon is important for inventories and C offset markets. Laser Induced Breakdown Spectroscopy (LIBS) may provide an efficient means to reduce processing and analysis time; however, a number of soil properties may influence C analyses. Understanding these influences is needed before LIBS is deployed for routine C analysis. The recovery of C was evaluated by adding different C materials to soil. Recovery of organic and inorganic carbon varied with the type of C-bearing compounds. Among the six compounds measured, NaCO3 had the highest recovery rate followed by dextrose. Recovery of inorganic C generally had greater recovery than organic C.R2 values ranged from 0.73 to 0.99 for organic C concentrations ranging from 2 to 15%. R2 values were above 0.97 for inorganic C concentrations from 2 to 8%. Detection of added organic C was affected by soil type. Soil C measured by LIBS was influenced by a number of soil properties. We evaluated the influence of soil water content, particle size, mineralogy, bulk density, plant residue, and inorganic particles on soil C measurement. LIBS may provide rapid and reliable measurement of total soil C; however, corrections for the influence of soil properties are needed for implementation.