This study aims to analyze the standardization of the member size in Joudo-do, Joudo-ji as an inevitable preparation for the formation of the Daibutsu style, the new construction method invented by Chogen. 1) Through the calculation of the percentage ratio of timber volume and structural timber volume, 9 kinds of parts which are more than 3% of the percentage ratio of timber volume are found in Joudo-do, Joudo-ji. 2) The percentage ratio of timber volume of 9 kinds of parts in Joudo-do corresponds to 64.68% of total timber volume, while the percentage ratio of structural timber volume corresponds to 60.63% of total structural timber volume. These volumes are approximately 20-30% lower than those of Nandai-mon, Kaisan-do and Shore, Todai-ji. 3) Therefore in Joudo-ji, Joudo-do there was not executed the standardization of the member size seen in Todai-ji.