The effect of some chemical changes in water quality were studied during two years (October, 2001 - August, 2003) and
recorded at six sampling sites situated at El-Zomor and El-Mariotya canals (branches from the River Nile). The aim of the
present work is to study the effect of some chemical parameters on the abundance degrees of some aquatic insects and
invertebrates in these two canals. Determination and estimation of the chemical parameters and abundance degrees are
carried out in the field and laboratory of Department of Entomology, Faculty of Science, Cairo University. Data of chemical
factors and abundance degrees of collected aquatic invertebrates were analyzed by using one-way analysis of variance
(ANOVA). The data obtained showed that, there is a strong correlation coefficients (P < 0.05 & r = 0.634) and (P < 0.10 & r
= 0.506) between electrical conductivity values and insects (Diptera and Odonata) that distributed in these two canals. The
semi-logarithmic graphs showed that the water quality of samples is changed to some extent where the chloride ions is higher
than bicarbonate and; sulphate, magnesium are higher than calcium and sodium during some reported months especially at
El-Zomor canal.