Objectives: The purpose of the study was to investigate the perception of clinical trials of dental hygienist. Methods: A self-reported questionnaire was filled out by 126 dental hygienists in Seoul, Kyonggi and other area from October 1 to November 15, 2012. The instrument of the study was adapted from Jung and reconstructed. The questionnaire consisted of general characteristics of the subjects(9 questions) and recognition for clinical trials(10 questions). Recognition for clinical trials instrument included recognition for clinical trial conception(2 questions), objective recognition(5 questions), and subjective recognition for clinical trial(3 questions). The instrument was score by Likert 5 scale and Cronbach alpha was 0.936 in the study. Data were analyzed by SPSS 20.0 program and set at p<0.05. Independent t-test, chi-square test, one way ANOVA, and post-hoc Duncan test were done. Results: Those who had higher ages and higher education tended to have longer clinical careers(p<0.05). There was a significant difference in clinical trials between the level of education, clinical dental hygienists and professors. The differences in problem perception for activation of clinical trial according to workplace appeared to lack of publicity and inadequacy of facilities(p<0.05). Conclusions: To improve the perception of the clinical trials in dental hygienists, it is necessary to prepare the human resources programs, the additional curricula, continuing education courses and active publicity.