This article explores ＂Sango＂ 產語, a book about economic thought written by Japanese Confucian Dazai Shundai 太宰春臺 (1680-1747). Firstly, based on my study in philology, I point out that the author of Sango is Dazai Shundai. Secondly, I analyze the structure of the thought in ＂Sango＂ and explain Dazai Shundai's economic policy in order to highlight his ideas on developing agriculture and controlling commerce. Thirdly, I investigate the relationship between Dazai Shundai's economics thought and the Sorai School 徂徠學派 for the explanation of why he wrote ＂Sango＂ and the values and the limits of it.