Abstract: A 4 X 4 diallel cross experiment involving three exotic lines i.e. Allepo 40, LB-546 and Coker-304 and one local line i.e. Express, was conducted to evaluate the gene action for different Agronomic & Fibre characters in upland cotton. Additive gene action with partial .dominance appeared to control plant height, seed index, fibre fineness, fibre length & lint index where as over dominance type of gene action was noted for ginning out turn percentage and number of sympodial branches. On over all basis Allepo-40 has maximum dominant genes for number of sympodial branches and lint index while dominant genes for plant height ,seed index and fibre fineness are present in LB-546.Coker-304 has maximum dominant genes for fibre length and ginning out turn percentage while Express did not have any dominant genes.