Cigarette smoking is the potential risk factor for lung cancer and chronic pulmonary disease, as well as inflammatory bowel disease and reproductive malfunction. Nicotine and tar have been im plicated as a major factor in the pathogenesis of the diseases. Nicotine increases heart rate and blood pressure due to stimulation sympathetic neurotransmission and tar also accounts for the severe damage of peridontal diseases and osteoporosis in postmenopausal women. Portulaca oleracea, which contains significant amount of K+, noradrenaline and dopamine as well as various nutrients, has been used for many medicinal purposes and one of which is the detoxification of insect or snake toxins. The purpose of this study was to investigate the action of Portulaca oleracea extracts on the reduction of harmful materials of tabacco. The reduction percentages were measured in the presence and absence of each solvent extract of Portulaca oleracea using reversed C18 column of HPLC. Nicotine reduction effects were obtained from aqueous, methanol and chloroform extracts of Portulaca oleracea as 89%, 55% and 51%, respectively. The results suggest that the polar extracts of Portulaca oleracea affects the reduction of nicotine which is responsible for many diseases.