Cotton varieties: Coker310, SP8886, Lachata, Montana, Halab33, CA22 and Cord26 along with their 21 half diallel hybrids were planted at Al-Hawija (Kirkuk Governorate) using Randomized Complete Block Design with three replications. Statistical analysis for data was done and variances and effects of general and specific combining abilities were estimated for characters: plant height, number of fruiting branches per plant, number of bolls per plant, boll weight, seed index, lint index, earliness and seed cotton yield per plant. The results showed that mean square of all genotypes (parents and hybrids), parents, hybrids and parents vs hybrids (each alone) was significant at 1% for all characters except number of fruiting branches per plant and boll weight in case of parents and earliness in case of hybrids in which was significant at 5%, and was not significant for number of fruiting branches per plant and seed index in case of parents vs hybrids. Mean square of general and specific combining abilities was significant at 1% for all characters. The variety Halab33 showed significant desirable general combining ability effects for six characters incluiding seed cotton yield per plant followed by CA22 and Coker310, and the hybrid (Lachata x AC22) was surpassed in its specific combining ability effects for all studied characters followed by hybrids ( Coker310 x Halab33) and (Montana x Cord26) which was surpassed for five characters incluiding seed cotton yield, that is an indication of possipilty of using these genotypes in breeding programs. The additive and non additive varianc components were significant from zero for all characters, and values of dominance components was higher than additive one for all characters except plant height and earliness. Graphic analysis suggested the presence of epistatic gene action (non-allelic interaction) for number of bolls per plant and earliness. Narrow sense heritability was high for plant height (51.157%), moderate for seed and lint indices, and low for other characters.