CD14, a pattern recognition receptor on monocyte and macrophage, plays a central role in innate immunity through recognition of bacterial lipopolysaccharide and initiation of inflammatory response. Recently, CD14/À260C4T promoter gene polymorphism has been found to be related to a risk of inflammatory diseases. Our results showed that the C allele frequency among Chinese in Taiwan was lower than those in Western countries. The membrane CD14 expression was significantly higher in TT as compared with CT and CC genotypes (P ¼ 0.034, 0.044, respectively). There was a higher level of soluble CD14 in TT and CT genotypes than in CC genotypes. In addition, TNFa production in whole blood was significantly higher in TT genotype than in CC genotype after stimulation by Chlamydiae. In conclusion, the single base pair polymorphism of CD14 promoter gene is associated with CD14 expression and Chlamydia-stimulated TNFa production, and may thus play some role in the chlamydia-induced inflammatory response.