In the present study, seminal plasma protein (BSP-A1/-A2) was isolated from six crossbred (FxJxBxH) bull semen by progressive purification using two stage chromatographic procedures. HBP and BSP-A1/-A2 were 30.9 and 24.1 per cent of total protein content (average of 90.1±5.6 mg/ml of semen). BSP-A1/-A2 was found to be more abundant than other BSP proteins. Antibody was raised against BSP-A1/-A2 and by blotting and immunodiffusion assay the eluted protein fraction was characterized.