Technical Abstract: Blueberries (BB) contain high levels of polyphenols. Among them, phenolic acids (PAs) have been recently suggested as a group of important bioactive compounds. Highbush BB (Vaccinium corymbosum) and lowbush “wild" BB (Vaccinium angustifolium) are two predominant species in North America. The first objective of this study is to systemically analyze and compare the profiles of PAs in these two species. Nine PAs were detected and quantified in both species by HPLC/MS; of these, five PAs were identified in BB for the first time. The total PA content of lowbush BB (4.90 mg/g, dry weight (DW)) is about 3.2 times higher than that of highbush BB (1.53 mg/g, DW). Chlorogenic acid is the most abundant PA in BB, at 4.87 mg/g DW and 1.12 mg/g DW in lowbush and highbush BB. Anti-inflammatory effects of polyphenol-rich extracts of the two BB species were evaluated by a SEAP reporter assay to measure NF-'B activation. An initial test using 10 µg/mL of extracts showed that lowbush and highbush BB inhibited LPS-induced NF-KappaB activation by 30.7 % and 16.8 % (P<0.05), respectively. Our data indicated that the concentrations of phenolic acids in the two major BB species are very different. Lowbush BB polyphenols exhibited greater anti-inflammatory potential than those of highbush BB. The anti-inflammatory effects of polyphenols in BB warrant further investigation.