Cotton aphids (Aphis gossypii, Glover) have become a major pest on the High Plains of Texas. The cotton producer is affected by increasing control cost as well as yield reductions. Another problem, lint contamination or "sticky cotton" is associated with aphid honeydew. Research was conducted to determine if the changes in the sugar and amino acid composition of cotton leaves during boll development were related to developing aphid numbers. Leaves developing under different water treatments and associated with fruit of various ages from flower to open bolls were analyzed for both chemical constituents and aphid densities. The results did not indicate a strong relationship between the biochemical composition and aphid densities on individual leaves.