A reference economic cycle is analyzed monthly. Although GDP is the most important indicator for measuring a national’s overall economy, data obtained quarterly and requires higher revision frequency and amplitude. Therefore, it is not advisable to use a single GDP indicator to measure fluctuations in economic cycle. In addition, since the identification of the reference date of business cycle should take into account economic indicator changes in all aspects of the overall economy, only through which a nation’s stepping into contraction or expansion in terms of overall economy can be identified. Therefore, the approach in Taiwan is to use a set of representative macroeconomic indicators to determine the reference date, while final confirmation is made using GDP data.