The first aim of the present study was performed to assay the activity of arginase in sera of women with uterine fibroid..   This study consisted of(50) women with uterine fibroid as patient's group  and (30) healthy women as control group. The age ranged between (30-55) years for the two groups. The results showed that highly significant increas (P< 0.0001) in the arginase activity in sera of women with uterine fibroid (7.99± 0.23) I.U/L is found when compared with healthy group (0.52±0.02) I.U/L. The second aim was performed to isolate arginase from sera of women with uterine fibroids. The purification is done by addition of ammonium sulfate, dialysis, gel filtration chromatography by using sephadex G-50 and ion exchange chromatography by using DEAE cellulose A-50. The results showed a single band for isoenzymes following steps by using sodium dodecyl sulfate- polyacryl amide gel electrophoresis (SDS-PAGE) .