Maize (Zea mays L.) is the second-most significant cereal crop after wheat in Egypt and wordwide. The aim of this study was to evaluate the genetic diversity among six maize inbred lines and their 15 F1s single crosses using Simple sequence repeat (SSR) markers by five SSR primers.The current investigation were conducted during two successive summer seasons of 2020 and 2021 at National Research Centre, Agriculture Research Station in Nubaria, El-Beheira governorate to produce all possible hybrid combinations. A total number of amplified fragments was 75 bands. Forty-six out of 75 bands were monomorphic (61.33%) and 29 fragments were polymorphic bands. The number of amplicons per primer varied between 6 (p-dupssr 7) and 23 (p-umc1358). The Jaccard's similarity coefficient separated the six maize lines and 15 single crosses (Sc) into two major groups. The first group I: Included three sub-groups: Sub-group a: (similarity range 0.72 to 0.84) consisted of Sc (P1xP4) and sub-group b (similarity range 0.78 to 0.87): contained two Sc (P1xP9) and (P1xP12). Sub-group c (similarity range 0.75 to 0.91) such as P1; (P1xP15); (P1xP17); and (P4xP15). The second group (II) composed of three sub-groups: Sub-group d (similarity range 0.72 to 0.90) involved P15; (P15xP17). Sub-group e (similarity range 0.70 to 0.91) included P17; (P12xP17); and (P12xP15). Sub-group f (similarity range 0.75 to 0.93) contained P4; (P4xP9); (P4xP12); (P4xP17); P9; P12; (P9xP12); (P9xP15); and (P9xP17). The SSR markers can be used as test of hybridity and seed genetic purity in the breeding programs of maize.