Abstract: Studies oily wastewater treatment in oilfields using polyamidoamine(PAMAM), a new type polymeric dendrimer flocculant. The results revealed that when used in minute amounts (15～20 mg·L -1 ) it could very effectively decrease the oil content, from 320 mg·L -1 to 1 mg·L -1 . Combining PAMAM with some natural polymer coagulator such as soluble starch or carboxyl methyl cellulose in the treatment of oily wastewater, the effect of removal could even be better than that of PAMAM alone, and the amount of PAMAM could be reduced to 5 mg·L -1 .