The present study was carried out at farm and laboratory of Animal Production Department- Faculty of Agriculture, Fayoum University, Egypt. Helianthus tuberosus in Ossimi rams rations were evaluated through digestibility, feeding values and some blood parameters. Ossimi rams weighed 45±5 kg in average were used to evaluate the rations supplemented by Helianthus tuberosus. The tested rations were D₁ (control) composed of 60% concentrate mixture (CM) + 40% wheat straw (WS); D₂, 52.5% CM + 7.5% Helianthus tuberosus (HT) +40% (WS); D_3, 45% CM +15% HT +40% WS and D_4, 30% CM +30% HT +40% WS. The results revealed that Ossimi rams fed rations of D₂ and D₃ showed higher significantly values (P<0.05) of most digestibility coefficients and feeding values compared with control ration. While, insignificant differences were found between D₁ and D₄ regarding digestibilities and feeding values. The obtained results of some blood parameters showed the same trend of rations digestibilities. Adding Helianthus tuberosus in the rations of D₂ and D₃ (7.5 and 15% HT) of Ossimi rams improved nutrients digestibility and feeding values and some blood parameters.