There have been at least three attempts to compile Taiwan's Consumer Price Index (CPI) in the Japanese colonial period, all by the Japanese scholar Mizoguchi. The compilation of CPI requires consumption expenditure ratios and price statistics. In his studies, Mizoguchi explains how consumption expenditure ratios are calculated, but little details are given on price statistics. In this study, extended sources of prices and household survey data are used to calculate consumption expenditure ratios. The new CPI in the rural area is significantly different from Mizoguchi's results.