The present study was conducted at Maryout Experimental Station at El-Amria Region, Desert Research center, Ministry of Agriculture, throughout the period from 2004 to 2006. The objectives of this research were  : to determine the heterotic effects of the reciprocal crosses among three strains including Gimmizah (GG) as a local strain, Rhode Island Red (RR) as a standard foreign strain and Kosmos (KK) as a commercial meat type strain on body weights at 4, 8, 12, 16 and 20 weeks of age and some carcass traits at 24 weeks of age, as well as to calculate each of strait –line difference, maternal additive effects and direct additive effect and calculate potency ratio values.    The results indicated that the cross of Gimmizah with Rhode Island Red had the highest positive average degree of heterosis for body weight of 28.01% at 4 weeks, 41.52% at 8 weeks and 19.77% at 12 weeks of age which could be due to over dominance of the Gimmizah and Rhode Island Red strains according to their potency ratio (RR) values which were 3.56, 9.65 and 4.24 at 4, 8 and 12 weeks of age, respectively. The values of average degree of heterosis (ADH%) were positive for live body weight (5.22%), drawing weight (0.46%) and eviscerated carcass weight (11.67%) at 24 weeks of age for the Rhode Island Red x Kosmos cross which could be due to dominance effects towards the high parent (Kosmos) where potency ratio value was 1.24. Using Kosmos strain as a dam strain in GK and RK crosses improved body weight trait at 4,8,12 and 16 weeks of age. Using Gimmizah strain as a sire strain in GR cross resulted in superiority of body weight at 4, 8, 12, 16 and 20 weeks of age, live body weight, eviscerated carcass weight % and edible giblets weight% at 24 weeks of age.