This research aims to study the properties of aggregates in different areas of eastern Libya, and their effect on the properties of concrete and its strength (compression, tensile and flexural), Three aggregates sample were selected from three different cities of (Al-Marj, Al-Bayar Al-Qubbah). The results of the aggregate tests indicated that the sample taken from Al-Qubbah is the best aggregate sample, and when comparing the results of the concrete tests for compression, it was found that the mixture used for the aggregate taken from Al-Qubbah increased by (5.86%, 8.73%), the results of the concrete strength test for tensile increased by (0.79%, 13.68%), and the results of the concrete strength test for flexural increased by (0.63%, 13.74%) than the mixtures aggregates from the cities of Marj and Al-Abyar.......... Keywords:........ Aggregate, compressive strength test, tensile strength test, concrete