In the present study we mainly aimed to investigate the function of the inferior frontal gyrus, by means of passively listening to Japanese words, nonsense words, English words, nonsense words respectively by Japanese subjects using functional magnetic resonance imaging (fMRI). English words and nonsense words activated the dorsal parts of bilateral inferior frontal cortex more extensive than Japanese words and nonsense words, which might imply the implicit silent repetition might take place during English stimuli listening for better perception. The ventral parts of left inferior frontal cortex were activated by Japanese and English words conditions than nonsense words conditions of the two languages confirms its function in lexical or semantic processing. We also found the activation of visual cortex by Japanese especially by the Japanese nonsense words than English, which may be correlated to the characteristic of Japanese in which the phoneme and grapheme are one-to-one mapping to some extent.