The present work was carried out at Sakha Agricultural Research Station during 1998 and 1999 seasons to know the extent of biparental mating system (North Carolina Design Ill) effectiveness in breaking unfa­bourable linkage groups and obtained new promising recombinations. In 1998 season, there were four sets, each set was consisted of five F2 plants as mate was group and each male was mated with the two par­eMs as females. In 1999 seasons forty biparental progenies were de­rived from crossing of 'Giza 88 x Pima Se F2 with their parents. Mean performance of biparental progenies F2 x Giza 88 exhibited higher values than those of F2 x Pima Ss and its parents (pure linos Gin 88 and Pima for seed cotton yield/ptant, ant yielcUplant, lint percentage, boll weight, seed index, lint index, mean length. miceonaire reading and yarn strength, while, boll weight, seed index, lint index, half fall, hair weight, mien:maim reading and yarn strength were larger In (F2 x Pina Se). Also. significant differences were found among the crosses of females (Giza 88 and Pima Se) with some mates for most studied traits and with most males for hair weight and half fall. Also, both seed cotton yield/plant and lint yield/plant with males No. 4 and 5 in set I and Ill. For mean length and micronairo readng with male 4 In set I and with males 2 and 3 in set Ill were significant. These results suggested breaking up the gene linkage block of some progenies of F.2 so we can obtain promising strains that have high yield. The variance due to paternal effect was larger than that due to maternal elect for most studied traits. The proportional contri­bution values of males were higher than those of females and its interac­tion for all traits. While, the proportional contribution values of females were Intermediate, it was higher than those Interaction males x females far seed cotton yleldfplant, lint percentage, tint index, mean length, half fell and micronake reading. The females x mates interaction was higher than females for lint yield/plant, boll weight, seed index and yam Strength. Additive variance was accounted for the largest major propor­tion of the phenotypic variance for all traits. These results show that ad­ditive effect playing the major role of the inheritance for these traits so direct selection could improve these hafts. Highly significant positive RA, RG and AP was obtained for seed cotton yield/plant with tint yieldrplant, boll weight, seed index and mean length. While, significantly negative val­ues were recorded with lint percentage, hall tall and micronaire reading. Also, the RD was positive with lint index, hall fall, hair weight and yam strength. Lint yield showed high positive RA, RG and RP with most traits, for lint percentage with boll weight, lint index hair weight and half fall. While, negative significant RA, RG and RP for kit percentage with seed index and mean length.