On the basis of the result of the opinion survey with the aim to assess the trend of citizens'attitude toward the use of nuclear energy, the authors analyze the trend of citizens' opinion for threeyears before and after the accident at Fukushima Daiichi Nuclear Power Plant (hereafter theaccident) on March 2011. Japanese citizens generally had accepted the use of nuclear energy beforethe accident, but a large number of them have been getting more suspicious about the future use ofnuclear energy after the accident. This change caused by the accident has continuously been seenover the three years after the accident.