A slurry dilution system with an ultrasonic vibrator capable of diluting slurry in-situ to any desired level of concentration is proposed. Raw slurry and the de-ionized water fed into the slurry dilution system is mixed and homogenized by an ultrasonic vibrator and a mixer. The well-mixed slurry solution is then delivered to a chemical-mechanical polishing station. When the chemical-mechanical station requires slurry of a different concentration, the raw slurry can be diluted to the desired level simply by changing the rate of flow of de-ionized water into the dilution system.