AbstractThis study explores the feasibility of in situ Lithium (Li) analysis in Magnesium‐Lithium (MgLi) alloys using Laser‐Induced Breakdown Spectroscopy (LIBS). It focuses on two Li emission lines: Li I 670.8 nm (resonance) and Li I 610.4 nm (non‐resonance). Comparing characteristics at atmospheric and low pressures, self‐reversal signatures are observed in both emission lines at atmospheric pressure, complicating the analysis. Challenges in suppressing self‐reversal effect using laser energy and detection window adjustments are noted. To address this, a compact chamber (80 mm×50 mm×50 mm) with adjustable pressure (using a portable vacuum pump) is developed. Lowering the pressure significantly reduces self‐reversal effect, particularly for the Li I 610.4 nm line. This makes Li I 610.4 nm more suitable for analyzing high Lithium concentrations in MgLi alloys. Using standard samples, such as LA91 (8 % Li) and LA141 (14 % Li), the study successfully obtains Li I 610.4 nm spectra with proportional Li emission intensities. Even with a commercially affordable time‐integrated charge‐coupled device (CCD) detection system, the results indicate the efficacy of this approach for in situ Li analysis in MgLi alloys.