Abstract:The pharmacological effect of aqueous extract of Polygonum capitatum has been studied.The experimental resultsshow that polygonum capitatum markedly decreases WBC and RBC in urine of pyelonephritis mede in rats,the deathrate of Escherichia coli infected mice,and the temperature of feverish rabbits. It has also been found that after oral ad-ministration of Polygonum capitatum the animal urine markedly inhibits the growth of Escherichia coli,but diureticaction of the herb has not been observed.