In order to investigate the adulteration of chinese herbal cold and antitussive preparations with synthetic chemical drugs. We collected randomly 152 samples from August 1986 to August 1987 in Taiwan area. The results from T. L. C. and U. V. Spectrophotometric amalysis indicated 5 from 152 samples (i.e. 3.28%) Were adulterated with synthetic drugs including caffeine and Acetaminophen.