This study was conducted from the beginning of the month November to the end of the month of December 2013. The sample was obtained from the Faculty of Science / University of Tikrit, the sample has been confirmed by using biochemical tests. And also conducted extracted DNA from bacteria P.aeruginosa to know the gene responsible for the production of pyocyanin and an electrophoresis that has led to the emergence of packages specific prefixes that indicate the presence of specific gene for pyocyanin in chromosome of P.aeruginosa. The results showed that isolated sample has produced the highest amount of the pyocyanin (23.41μg/ml). We studied the effect of pyocyanin on the growth of some types of bacteria and the results showed that the pyocyanin an effective impact on the inhibition of the growth of bacterial species including, Escherichia coli, E.faecalis Staphylococcus aureus, Salmonella typhi, and also had an impact on bacteria P.aeruginosa.