Abstract: In this paper, cellulose acetate electrophoresis and UV spectrophotometry were used to determine Gentamicin in foam extracted by BSA. In UV spectrophotometry method, 620 nm was selected as a criterion for quantitative determination. The results indicated that there is a better linear relationship between the absorbance and the concentration of the sample with the condition that combo concentration of gentamiein and amino black 10 B was 1.25 to 10 μg/mL, the correlation coefficient was 0.999 6, and the mean rate of recovery was 100.59 %.