This research aimed to identify the expected effects of the construction of the Grand Ethiopian Renaissance Dam on the fish resources system in Egypt, Field data were collected in Aswan and Dakahlia governorates using a questionnaire through personal interview during the period from May to October 2020, for two groups of respondents, a simple random sample of specialists that amounted to 45 specialists from the total of 60 specialists are representing 75%, and a simple random sample of experts amounted to 30 experts from the total of 50 experts are representing 60 %, The frequencies, percentages, range, mean, standard deviation, relative weight, and Mann-Whitney test were used to analyze the data, the most important results obtained were the following: 1- The results showed, according to the opinions of the respondents, the existence of a high relative weight effect on capture fisheries and fish farms. 2- 80 % of the specialists indicated that the expected effects of building the Renaissance Dam on the fish system were great relative importance, while 56.7 % of the experts indicated that these effects were moderate relative importance.3- It became clear that there are no significant differences between the averages in the ranks of the opinions of specialists and experts regarding the expected effects of building the Ethiopian Renaissance Dam on the fish resources system in Egypt.