In radiation therapy, investigating of the effects of the surface flux reaching on the tissue is important in planning the treatment and this requires a precise evaluation of the absorbed dose distribution throughout the irradiated tissue. Therefore, by Monte Carlo simulation with MCNP code, a point source with the size of E with a spectrum width of 0.6 µm with a single energy transfer of 6 MeV to the breast tumor tissue with a size of 2 x 4 x 4 cm and also a density (Kg/m^3) of 11.34 at a fixed depth of 3 cm. It is radiated from a standard phantom (VIP MAN) made of tissue. The results show the highest surface flux that received on the tumor is around 9.97 × 〖10〗^(-6) and is located almost in the center of the tumor in dimensions (-0.75 cm - 1.3 cm) and the less surface flux around the tumor is caused by the rate of the dose which is distributed. Also, the template phenomenon in the creation of electrons is based on the Compton effect, while in the creation of photons, the Compton effect did not occur. تفاصيل المقالة