There are provided 4-alkynylimidazole derivatives represented by the following general formula (I) or phamaceutically acceptable salts thereof; the derivatives have a superior EP4 receptor antagonistic action and are useful as pharmaceuticals for the treatment of diseases associated with the EP4 receptor, for example, as anti-inflammatory and/or analgesic drugs for inflammatory diseases and diseases that involve various kinds of pains, and further as pharmaceuticals for the treatment of immune diseases that result from inflammations as evoked by tissue destruction due to the activation of Th1 cells and/or Th17 cells: