Field experiments were conducted at Arab El-Awamer, Abnob, Assiut governorate, Egypt (semi-arid newly reclaimed lands) during the 2020 and 2021 growing seasons, to study some ecological aspects of main pests and their associated natural enemies inhabiting kidney bean, Phaseolus vulgaris L. Results recorded forty-one arthropods belong to twenty different families and ten orders injury on kidney bean plants. The main insect pest species included twenty-seven species belong to fourteen families and nine orders and natural enemies included fourteen species of nine families and seven orders. In addition, the results showed that; Aphis sp., Thrips tabaci (Lind.), Empoasca sp., Nezara viridula L., Liriomyza sp., Bemisia tabaci (Genn.) and Tetranychus urticae Koch were the key insect and mite pests recorded on kidney bean plants. The dominant natural enemies were Orius sp., Scymnus sp., Chrysopa sp., Coccinella sp., Paederus alfierii Koch, Scolothrips sp. and Predaceious mites found on kidney bean plants. Aphis sp. and T. urticae were the main pests in the highest average number of individuals followed by Liriomyza sp., Empoasca sp., B. tabai, N. viridula and T. tabaci during the 2020 and 2021 growing seasons. Results also indicated that the correlation between preceding key insect pests and their natural enemies was a strong significant positive or negative correlation between of them. It can be concluded that there are major numbers of natural enemies that can play a significant role in Bio control of the key pests afflicted kidney bean plants to avoid danger to the environment with insecticides.