Chemical analysis of ( carbohydrates ,protein, pH and amino acids) in three tested varieties of wheat plant( Sakha94,Giza168 and Balady) on the rate of infestation of some homopterous insects i.e. aphid insects (Rhopalosiphum maidis and R. padi ) and leafhopper insects(Balclutha hortensis, Empoasca decipiens and E decedens)was studied in order to clarify the importance of these chemical constituents on the rate of infestation and subsequently the effect on the quality of yield of these plants. These results showed that these were differences between the tested wheat varieties and the number of these insects.The Balady variety showed the highest infestation with the aforementioned insects ,while the Sakha94 was infested with the lowest number of the insects .There were significant difference between the aforementioned of all three varieties and the infestation with the tested insects. Chemical analysis results recorded a positive relationship between protein , carbohydrate contents, and amino acid and infestation ,while a reverse relation was recorded with pH values. Large differences were found between amino acids concentration in the three wheat varieties especially Proline, Serine , Aspartic acid and Alanine which were obviously between Balady variety and Sakha 94 variety.Highly significant positive correlation between aforementioned insects and free amino acids except Methionine , Cysteine and Phenylalanine the correlation was non-significant. Although, the total amount of amino acids present in phloem sap was low but they were a limiting factor for aphids and leafhoppers growth . Preliminary data on present work highlights a dependent .relation between plant quality and aphid and leafhopper number on three wheat varieties .