Abstract: The study of Genetic improvement of local chickens by crossing with the Label Rouge was carried out on the Experimentation Farm of the Polytechnic School of Abomey-Calavi, from August 2007 to may 2008. At the hatching, 6 lots of chicks were made up: the lot MnFl, composed of 47 chicks resulting from the crossing between females Label Rouge and males of North ecotype; the lot MlFn, composed of 58 chicks resulting from the crossing between North females and males Label Rouge; the lot MsFl, composed of 36 chicks resulting from the crossing between Label Rouge females and males of the South ecotype; the lot of north local chickens composed of 112 chicks; the lot of South local chickens composed of 128 chicks and the lot of Label Rouge composed of 204 chicks. Label Rouge have an age-type weight significantly higher than the cross ones (p<0.05) and those have also an age-type weight more significant than the local chickens (p<0.01). The Label Rouge had more important feed intake than the local chickens and the crossbreeds had a feed intake intermediate between the ones of the Label Rouge and the local chickens. Among the chickens resulting from a parent of North ecotype, the hens resulting from a cock of North ecotype had a weak feed efficiency compared to the one resulting from females of North ecotype. The weight average heterosis was 21.95, 14.47 and 27.69%, respectively for the cross MnFl, MlFn and MsFl. Those of the female were 1.17; 23.2 and 4.62%, respectively for the cross MnFl, MlFn and MsFl. A negative heterosis effect was obtained for the feed intake and the feed efficiency of the various crossbreeds.