Specimens of veneridae clams were collected from Lake Timsah (Suez Canal). These specimens were classified by morphological investigation to seven species, six genera and four subfamilies. Some specimens had shell abnormalities (about 5-7% out of the collected specimens) as response to contaminants exposure in their habitat. Random amplified polymorphic DNA (RAPD) markers were used to determine the genetic similarities between the collected species. 13 out of 21 RAPD primers generated 368 RAPD markers ranged from 130 to 2073 bp. The genetic similarity index values revealed non-significant differences in the genetic diversity between species (the value between each two species was above 0.5) The high values of similarity proved that, the collected species must be actually monophylogenetics. The similarity value between some species was higher than the others; despite these species follow different subfamilies. On the other hand, although two species follow the same genus, their similarity value was lower than that of them and the rest of the species. The unweighted pair group method using arithmetic average (UPGMA) dendrogram based on the genetic similarity index comprised two main clusters, one of which nested large cluster including six species, and the other included only one species.