Objectives : This study was designed to evaluate the pesticide residue of herb medicine through high density ozone water cleaning system. Materials and Methods : We purchased ginseng(Panax ginseng) on market and sprayed pesticides (Diazinon) on ginseng. We analyzed pesticide residue according to washing methods(untreated, ozone water cleaning, ultrasonic cleaning, Water cleaning). As a result of each washing methods, in ozone water cleaning method pesticide residue was much less remained than in Ultrasonic Cleaning method and water cleaning method. Conclusions : High density ozone water cleaning is the best method for removing pesticides of herbal medicine.