During the last few decades, a variety of medical scanning devices has been made and each, considering its unique features, has many applications. Methodology: In this paper efforts have been made to use Monte Carlo method to simulate the trajectory of the photons in biological tissue. New features were added to the Monte Carlo simulation. In this paper, of the most prominent features of simulation, changing the angle of incident beam to the tissue, selecting multilayer tissues, and choose the type of tissue could be named. In this study the results compared with others and the also the effect of anisotropy on the optical properties of the tissue were examined. Results: The results obtained with this code, even using a relatively small number of photons, compare favorably with those obtained elsewhere. The code can be changed so that the number of grid points is read as data input. It is worth emphasizing though that, with the option of running the Monte Carlo simulation directly from the code. Conclusion: the results obtained with the Monte Carlo simulation for different entry angles. No similar calculations have been found in the literature for a comparison to be possible. Our results seem to indicate that the diffuse reflectance and absorbance increases with decreasing angle while the transmittance decreases.