Insight is universal. It is also one of the components of creativity which lies at the core of numerous discoveries, such as, Archimedes’s discovery of the law buoyancy, Newton’s finding of the law of gravitation or Kekulé’s discovery of the ring structure of benzene. However, it attracts relatively little attention. Although gestalt psychologists have gotten path-breaking findings by phenomenal observations, until about recent ten years, a few studies have started to explore the cognitive process or mechanism of insight problem solving. The current study adopted normal three-word Chinese riddles and employed high-density event related potentials (ERPs) to detect the neural correlates of insight involved in problem solving. ERP waveform analysis revealed that, in the time course of 320-550 ms, “Aha!” responses elicited a more negative defection (N380) than No-aha ones did. For the difference wave, the latency of the negative defection was 380ms, and maximum amplitude located at Cz. Time-frequency analysis showed that, there were an decreased gamma power and an decreased upper beta power associated with N380 in the range of 320~550ms. Independent component analysis indicated that, there were four dynamic but independent dipole source related to N380 during its time course, which located at right middle frontal gyrus, left inferior parietal lobule, right superior temporal gyrus and left inferior frontal gyrus, respectively. These results suggest that the N380 is the N400, and is responsible for transformative processing from explicit meaning into metaphoric meaning in the three-charter riddles.