This investigation was carried out at Sakha Experimental Station, Agricultural Research Center during four seasons 2013, 2014, 2015 and 2016. Five populations (P1, P2, F1, F2 and f3) for the four barbadense cotton crosses namely (Uzbekstanl x C.B 58), (TNB x C.B 58), (BBB x C.B 58) and (Giza 94 x Giza 45) were~ used in this investigation to study the genetic behavior of yield and its components and fiber traits. The aim of the present investigation was to study heterosis, inbreeding depression and type of gene action in four intra-specific crosses to obtain additional information about some genetic parameters to help the breeder to select effective breeding methods. The results showed that the potence ratio estimates indicated over dominance for seed cotton and lint yield/plant, boll weight, lint percentage and number of bolls/plant, while the quality traits exhibited partial dominance. Highly significant positive heterotic effects relative to mid-parent and better parent were obtained for seed cotton yield, lint cotton yield and number of bolls/plant, while it was for lint percentage. The inbreeding depression effects were highly significant for number of bolls/plant, seed cotton yield and lint cotton yield. Highly significant values of additive and dominance were found for seed cotton yield, lint cotton yield and number of bolls/plant. Dominance effects for Micronaire value and fiber length were of greater magnitude than additive effects. Highly significant epistasis values were found for additive x additive and dominance x dominance with complementary action with non additive effect. High broad sense heritability values were calculated for all studied traits, while narrow sense heritability values were of low values for seed cotton and lint cotton yield. on the other hand the fiber quality traits exhibited high values in three crosses as well as the heritabilities of regression. [ABSTRACT FROM AUTHOR]