Objective To optimize experimental parameters for the photosensitization of 52aminolevulinic acid (ALA) in promyelocytic leukemia cell HL60 and compare them with normal human peripheral blood mononuclear cell (PBMC). Methods ALA incubation time, wavelength applied to irradiate, concentration of ALA incubated, irradiation fluence may modulate the effect of 52aminolevulinic acid based Photodynamic Therapy (ALA2PDT). The high2pressure mercury lamps of 400W served as light source, the interference f ilter of 410 nm, 432 nm, 545 nm, 577 nm were used to select the specif ic wavelength. Fluorescence microscope was used to detect the fluorescence intensity and location of protoporphyrin IX (PpIX) endogenously produced by ALA. MTT assay was used to measure the survival of cell. Flow cytometry with ANNEXIN V FITC kit (contains annexin V FITC, binding buffer and PI) was used to detect the mode of cell death. Re sults ①1 mmol/L ALA incubated 1×105/mL HL60 cell line for 4 hours, the maximum fluorescence of ALA induced PpIX was detected in cytomembrane. ② Irradiated with 410 nm for 14. 4 J/cm2 can result in the minimum survivability of HL60 cell. ③ The main mode of HL60 cell death caused by ALA2PDT is necrosis. Conclusion 　ALAfor 1 mmol/L, 4 hours for dark incubation time, 410 nmfor irradiation wavelength, 14.4 J/cm2 for irradiation fluence were the optimal parameters to selectively eliminate promyelocytic leukemia cell HL60 by ALA based PDT. The photosensitization of ALA based PDT caused the necrosis of HL60 cell, so it could be used for inactivation of certain leukemia cells.