Objectives : To document the use and out-of-pocket expenditure of complementary and alternative medicine(CAM) in Korean adult population. Methods : Nationwide, random-sampled, and population-weighted telephone survey was conducted. The sample size of respondents was 1,000(age over 18). The respondents were asked about their use, out-of pocket expenditure of CAM in the past 12 months. SAS 8.0 statistic package was used for checking the relevance between each variables by performing $x^2-test$ and variance evaluation. Results : In 2001, 64.0% of people experienced more than one alternative therapy and the beneficiary took therapy average figure of 2.07. Alternative therapies were generally used for health promotion(73.7%) rather than curing the disease(26.3%). The most common therapies included Medication(30.2%), Physical-therapy(21.9%) health implements(20.8%), herb medication(19.2%), diet therapy(14.3%) etc. Average annual out-of-pocket expenditure was ￡<192,186. Use varied according to age, living province, income, and education, while cost expenditure did according to sex, health condition, income, education. Conclusions : The use of CAM in Korea is very large and the expenditure for them is 22.6% of national medical expenditure. It shows great need of political and academic approach.