We present a method for quantitative tracking of phagosomes without labeling. Current imaging methods, used for phagosome research, have limitations in live-cell quantitative analysis. We reconstruct three-dimensional (3-D) refractive index (RI) tomograms from two-dimensional holograms with changing illumination angle. RI information enables to obtain intracellular phagosomes quantitatively. Time-lapse imaging provides 3-D information's of phagosom movement. Collectively, we propose that quantitative phase imaging techniques can be a useful tool for phagocytosis research.