This study was conducted at the Poultry Research Unit (EL-Bostan farm), Department of Animal and Poultry Production, Faculty of Agriculture, Damanhour University. The point of the work were to estimate direct heterosis maternal effect and direct additive effect of growth and reproduction traits in the local chicken strain Sinai (SI) through crossing with Alexandria (AL) strain raised under Egyptian environmental conditions. Percentage heterosis estimates for body weight were the highest at 8 weeks of age (30.17%) and declined at 12 weeks of age (9.9%). Estimates of direct heterosis for egg production trait were associated with significant negative heterosis. Percentage heterosis was 37.56% for age at sexual maturity (ASM) and 40.34% for egg mass. Maternal effect on body weight at different ages was significant. Body weights of chickens from Alexandria line mothers were significantly superior to those from Sinai line mother. Maternal effect of egg production traits was significant on ASM, egg number through 90 day and egg mass.  In conclusion, our results suggest that crossbreeding by mating of Alexandria sires with Sinai dams is recommended to improve egg production trait, while mating of Sinai sires with Alexandria dams is recommended to improve growth traits.