Abstract: This paper studies the behavior of anode bubbles by transparency cell. Anode bubbles grew gradually at anode bottom. The bubbles generated on anode side were smaller than those of anode bottom. Obvious phenomena that diameter of anode bubbles opposite to the cathode was the smallest in all bubbles were observed. The bubbles generated on the anode surface don't collect into bigger bubbles, which is different from the bubbles generated in other parts of anode. The bubbles generated at anode bottom overflow electrolyte by moving between anode and cathode. The diameter of anode bubbles affects cell voltages. Cell voltage increases by 0.21V with diameter of anode bubbles increasing 3 mm. The cell voltage changes by 0.16 V when anode bubbles generated at anode bottom separated from anode at 0.5 A/cm². The value was 0.12 V at 0.3 A/cm².