Background. Taiwan Food and Drug Administration discovered an illegal-use of DEHP and DBP in food and nutrition supplement in 2011. Although most of the contaminant products were removed and set regulatory action immediately, monitoring of phthalate exposure in human specimen is necessary to evaluate the actual exposure level of phthalates in Taiwan population. In 2013, we aim to conduct an exposure assessment study of phthalate in Taiwanese using bio-samples of representative population. Material and Method. We used population to size to select representative Taiwan population aged above 7 years old in 2013. First morning urine samples were collected for analysis of 11 phthalate metabolites, such as MEHP, MEOHP, MEHHP, MECPP, MiBP, MnBP, etc using on-line LC-MS/MS. Serum sample was analyzed for TSH, T4, T3, FT4 and TBG using chemiluminescent microparticle immunoassay (CMIA). An-interview questionnaire was also applied to obtain participant's demographic information, environmental exposure, life style, etc. Results and Discussion. Median levels (μg/g creatinine) of MEHP, MEOHP, MEHHP, MiBP and MnBP in 291 urine samples were 7.93, 22.0, 12.7, 9.47 and 17.9, respectively. We found that the median levels of MEHP, MEHHP, MEOHP in aged above 18 years old was significantly increased with age, whereas those of MnBP and MiBP in our subjects was significantly decreased. Median levels of MEHP and MiBP in Southern area were significantly 2-fold higher than those in Northern area. Serum T4 in adults (n=267) were significantly negative associated with urinary sum MEHP (ß=-0.140, p=0.023) and MnBP (ß=-0.136, p=0.025). About 5 % of adult have exceeded TDI of DEHP or DBP. Our findings indicate that the exposure of DEHP and DBP in Taiwanese adults are varied by age and region, possibly affected by different lifestyle, and may affect the thyroid hormones in adults.