Abstract: Se sources (Se-enriched probiotics, SP and sodium selenite, SS）were added into basal diet at 0.2, 0.5 and 1.0 mg/kg of Se. Feeding test lasted for 35 days. The results showed that the addition of either SS or SP significantly increased Se content in spleen. With an increase of the supplemental Se level, the Se content in spleen had a significant increase. Supplemental SP had a more significant action to increase Se content in spleen than SS. On days 14, supplemental Se from either SS or SP significantly promoted the T lymphocyte transformation in hen peripheral blood. With supplemental Se level increase, the T lymphocyte transformation were increased. On days 14 and 28, supplemental Se from either SS or SP significantly increased the plasma IL-2 level of hen. With supplemental Se level increase and the extension of experiment duration, the plasma IL-2 level also significantly increased. On days 28, there was a more significant increase in the plasma IL-2 level of hens fed by SP than that of hens fed by SS. The conclusion is that supplemental Se from either SS or SP significantly increased Se content in spleen, significantly promoted immune function of hen. With supplemental Se level increase, the effect was better. With the extension of experiment duration, supplemental SP had a better effect than SS.