We have been studying complex phenomena on flows of vesicles suspending to blood in micro circulations. In this paper, the distribution of vesicles at an orthogonal bifurcation is investigated in terms of numerical simulations by using real-coded lattice gas model, and we study its dependency on both the concentration of vesicles in the mother vessel and the diameter-ratio between two daughter vessels. Focusing on the ratio between the number of vesicles at each bifurcated vessel, it obeys the function of the third power of diameter-ratio of two daughters except the small diameter-ratio case. This might indicate that the flow ratio between two daughters would be the main physics on the dividing concentration of vesicles at the bifurcation.