Manganese in the low alloy steel was analyzed quantitatively using micro-laser-induced breakdown spectroscopy. The spatial resolution of 20 μm and the single pulse limit of detection of 0.10% were obtained. The calibration curve of Mn was established with basic calibration method, with determination coefficient (R2) of 0.97. The average relative error of Mn concentration prediction on 7 samples is 12.91%, and the root-mean-square error of cross-validation (RMSECV) is 0.11%. The R2 reaches 0.99 when using internal calibration method, as well as the average relative error of Mn concentration prediction on 7 samples and RMSECV were decreased to 7.25% and 0.07%, respectively. These results show that MicroLIBS technique is an effective approach for material surfaces quantitative microanalysis.