Objective To explore whether the placebo-controlled trials in traditional Chinese medicine (TCM) were scientific and ethical. Method An electronic search concerned with placebo-controlled trials of TCM was performed at Chinese Journal Full-text Database, Chinese Scientific and Technological Periodical Database (VIP), Wanfang Database and Chinese Bio-medicine Database (CBM) from January 1979 to April 2008. In addition, we handsearched the trials in specialized journals of TCM. The trials were assessed regard with their scientificalness, ethic and traits of TCM of placebo-controlled trials. Results A total of 231 trials were included, occupying about 2.09% of all the randomized controlled trials (RCTs) of TCM; among which there were 79 (34.20%) with sequence generation, 10 (4.33%) with allocation concealment, 129 (55.84%) with blind methods; 106 (45.89%)with basic intervention, 13 (5.63%) with criteria of intervention quality control, 139 (60.17%) with preparation of placebo, 10 (10.33%) with aggravating scheme, 70 (30.30%) with syndrome type of TCM, 48 (20.78%) with the outcome measurement of TCM. There were 48 RCTs (20.78%) were not scientific. There were 221 RCTs without institutional review board and 187 RCTs without informed consent. Conclusion Placebo-controlled trials of TCM are not applied extensively, and some of them are not scientific. Most of than do not meet the ethical requirements.