Abstract: In most casses the ice will turn opaque if the water contains certain guantity of air.The erperiments were carried out using the cryomicroscopy.Smples of twice-distilled water were hold between two piece of glass.The freezing theges under different cooling conditions were captured by a video canera.Results showed that the cooling rate was the main factor that influenced the size and distribution of air bubbles.Influences of the quantity of air dissolved in the water before freezing were also discussed in the paper.

Key words: Freeze Air bubble Cooling rate