Genetic diversity was studied in 31 Iraqi common reed samples , which were collected from Iraqi marshes in Basrah , Messan and Thi-Qar provinces and also from different areas in Baghdad province . Random amplified polymorphic DNA (RAPD) technique was used for evaluation of genetic diversity between collected samples . Seven primers were used for polymorphism detecting between common reed samples . The results revealed 102 bands for the all samples when RAPD-PCR was used . The percentage rate for the monomorphic bands is 6.86% , while the percentage rate for the polymorphic bands is 93.13% , and the numbers of these bands are ranging between 10 to 17 for each used primer .  The UBC1 primer gave the highest number of polymorphic bands with 17 bands , while the  M13 and Op-B01 primers gave the lowest number of polymorphic bands with 10 bands . The mean value of polymorphic bands is 13.5 for each used primer , while the percentage mean ratio for polymorphism is 92.67% , ranging between 71.42% for M13 primer and 100 % for UBC1 and Op-B11 primers . The results of dendrogram analysis for the RAPD data by using unweighted pair-group method with arithmetic average (UPGMA) were showed that almost common reed samples were distributed in six main groups with 60% in similarity . These six groups showed coincidence with their geographic area . The samples which collected from one location or from same province were clustered in one group , while the Meshab and Sallal (Basrah) isolated samples were segregated from the other samples . The genetic variations between isolated common reeds have advantage in weeds control by using chemical or other methods