The trial was carried during 2011-2013 on the second experimental field of the Institute of forage Crops-Pleven, Bulgaria. Populations of P₁, P₂, F₂ and F₁ of the crosses Shtambovii × Pleven 10 and Rosacrono × Pleven 4 and their reciprocals were investigated. Heterosis for the investigated traits was found in the hybrids of F₁ generations. The cross Rosacrono × Pleven 4 had the highest positive true heterosis for plant height (31.54%), height to first pod (15.44%) and pod length (17.11%); the cross Shtambovii × Pleven 10—for nods per plant (56.10%) and pod width (20.38%); Pleven 10 × Shtambovii—for 1000 seeds mass (14.65%) and Pleven 4 × Rosacrono—for number of seeds per pod. In F₂ the plants from Rosacrono × Pleven 4 had the strongest depression for plant height (28.26%), height to first pod (27.74%) and pod length (18.13%); Shtambovii × Pleven 10—for 1000 seeds mass (32.22%) and number of seeds per pod (13.87%). The stability of the studied characters was determined. Their variation in F₁ in the hybrid combination between Shtambovii andPleven10 was higher than F₁ of Rosacrono and Pleven 4. For more traits in direct crosses variability was found to be lower in relation to the reciprocal crosses in both combination. The genetical part in phenotipycal expression for height to first pod (Pleven 10 × Shtambovii), pod length and number of seeds per pod (Pleven 4 ×