The segregation phenomena of a binary mixture in a vertical vibrated bed were investigated experimentally by using image technology. The larger particles tend to move upwards and the smaller particles move downwards due to particle reorganization. The maximum segregation ratios at different vibration acceleration amplitudes were measured and analyzed. The segregation coefficients and the vertical velocities of the larger and the smaller particles were also measured. The segregation coefficient is increased with time until reaching a maximum value. The segregation rate and the velocities (absolute values) of the larger and the smaller particles are decreased with time, and finally become zero.