The heterotic performance of parents estimated to determine the performance of cotton in line X tester combinations and to determine heterosis for identification of potential genotypes for hybrid crop development in cotton. Two types of heterosis are estimated, the heterotic effect for the F1 hybrid upon mid parents and better parents relative heterosis and heterobeltiosis. The analysis for x line tester was performed to observe the influence of parents over hybrid with a combination of cotton. Total 7 parents including 4 lines with 3 tester and their 12 replications in Kharif season were grown at Shah Latif experimental areas Sindh Agriculture University, Tandojam in 2011. In this investigation the traits including the height of the plant, sympodial branches per plant, monopodialbranches per plant, bolls number per plant, yield of cotton seed per plant, ginning outturn percentage, sex index and staple length.Regarding heterotic estimates, crosses Bt. NIAB-777 x Sadorigave maximum heterosis for plant height, sympodial branches, seed index, lint index and Bt.CIM-595 x CIM-506 manifested maximum heterosis for G.O.T%, seed index and lint index. Other hybrids, Bt.886 x CIM-506 demonstrated high heterosis for sympodial branches, boll weight and staple length and Bt. NIAB-852 x sadori for monopodial branches, G.O.T% and Staple length. The high heterosis displaying hybrids may be exploited for hybrid vigor for various characters.