The effects of mixing rate, mixing time, concentrations of foam stabilizer xanthan gum (XC) and homemade surfactant DBA2-12 on the size of microbubbles were investigated using microscopic-imaging technique combined with Nano Measurer1.2 size analysis software. The results showed that high mixing rate and increasing XC concentration were beneficial to generate homogeneous distribution, fine and stable bubbles. However, the bubble size did not change significantly as the mixing time and surfactant concentration different. The optimum reaction condition of microbubble system was obtained as follows: 0.4% sodium carboxymethylcellulose (HV-CMC), 0.4% XC, 0.2% DBA2-14, 10000 r/min mixing rate and 2 min mixing time. The corresponding size of microbubble was between 23.58 μm and 109.65 μm with a mean size of 71.87 μm。The microbubbles would slowly grow bigger with the lapse of standing time, but its size did not exceed 200 μm after 12 hrs .