Photodynamic therapy is one of outstanding cancer healing method that potentially to replace chemotherapy. This method was utilizing a light and photosensitizer that directly damage the cancer cells with minimal annihilation of normal cells. In this present research, we try to determine the dose of blue laser energy diode 405 nm and exogen photosensitizer which generally used in photodynamic therapy for in vitro breast cancer healing. We use Chlorophyll a which was extracted from sirsak leaf and Protophorphyrin IX (PpIX) as photosensitizer. The Chlorophyll a has maximum absorbance at blue and red visible light about of 411.5 and 669.5 nm, respectively, while PpIX has 403 and 630 nm, respectively, which suitable for photosensitizer. We use the concentration of photosensitizer around 12 and 1.2 μl per sample for Chlorophyll and PpIX, respectively, which was obtained from the toxicity test. We also use the distance between laser and sample about 3 cm with the laser output power and beam size of 13.99 mW and 0.170009 cm2, respectively. While, the dosage of radiated energy was in the range of 2-148.14 J/cm2. We found that when we use laser radiation energy of 148.14 J/cm2, the percentage of mortality yields was obtained around 66.86% and 83% for laser with the addition of chlorophyll a and PpIX, respectively. The results indicate that the dosage of blue laser diode and proper choice of photosensitizer is important in photodynamic therapy.