Анотация: The experiment was performed in the Poultry Breeding Unit at the Institute of Agriculture, Stara Zagora, in 2009-2010. Three different chicken genotypes obtained by a specific plan were used: line R and line T from the Rhode Island Red breed and line N from the Rhode Island White breed. For each line, 20 selection nests with 12 hens and 2 cockerels (one principal and one spare) were formed. On the basis of observed zootechnological parameters, the line T was found to be superior to the other two lines with the highest live body weight of hens and cockerels and the lowest feed consumption per egg. Line N exhibited the highest hen-housed egg production rate, the intensity of egg laying, the age of egg laying`s start and hatchability. The fertility or eggs produced from this line was higher than that of Line N by 7.94 percentage, whereas the hatchability of fertile eggs was by 2.19 percentage higher than that of Line P. The egg mass for Line P and Line T with 60.90 g and 60.24 g (р< 0.01) was superior to Line N