Malodor, defined as an unpleasant oral odor, is a commonly experienced condition with a variety of etiologically factors and may cause a significant social or psychological handicap to those suffering from it. The aim of this study was evaluated to reduced malodor using a professional plaque control. This sample has a visiting patients of Dept. preventive dentistry of the Chosun University Dental Hospital during 2002-2004. Subjects were 64 selected patients (F: 37, M: 27) who came to complaints of malodor, have not physical disease and medication records. Subjects have treated by professional tooth cleaning method with meseaured volatile sulfur compounds(VSC) and treated 2 times per 2 weeks. All statistical siginificance were calculated non paramentric method by 95% level. The Result were as follows: 1. In serious malodor group, hydrogen sulfide was reduced about 10 times after 2 weeks(p>0.05). 2. In middle malodor group, dimethyl sulfide was reduced more about 10 times after 4 weeks(p<0.05). In weak malodor group, methyl mercaptan was reduced about 10 times after 4 weeks(p<0.05). 3. After 4 weeks, total volume of VSCs reduced 18 times in serious malodor group, 1.2 times in middle malodor group, 3.5 times in weak maldor group. 2 times in threshold or malodor strangeness group(p<0.05). 4. The mean of reduced pocket depth was 0.27mm, the rate of reduced bleeding on probing was 16.54%. From this result, this study suggests that professional plaque control method which was the reduction of malodor should be reinforced to increase oral health.