Abstract: A Study on the Extractive Methylation of 6 Diuretics and Probenecid Using GC/MSDYang Shumin;Zhu Saotang (National Research Institute of Sport Medicine,State Physical Culture and Sports Commission,Beijing 100029,China) Abstract:Using GC/MSD this paper dealt with the extractive methylation of 6 diuretics and probenecid which are forbidden in sports competation by IOC. Conditoin optimum and comparing researches were conducted and a practically usable method of these drugs was set up. Among these drugs probenecid,mefruside and ethacrynic acid can be detected in quite high sensitivity.Keywords: GC/MSD, extractive methylation, diuretics