This research aimed at comparing synchronicity of macroeconomic variables among five ASEAN countries comprising Indonesia, Malaysia, the Philippines, Singapore, Thailand and Japan, by using secondary time-series data from 1980-2010, totaling 31 years. Data were collected from the International Monetary Fund (IMF) and the World Bank and analyzed by Pearson Correlation Coefficient. The result reveals that there was synchronicity in macroeconomic variables among ASEAN members and Japan in terms of real GDP growth, degrees of openness and inflation rate, while the variables which had low synchronicity were the change of local currency per USD and real interest rates. When considering each country, it was found that Indonesia, Malaysia, Singapore, Thailand and Japan were countries having synchronicity of economic variables. However, the Philippines had low synchronicity. In addition, ASEAN and ASEAN plus Japan had similar synchronicity of macroeconomic variables. Therefore, ASEAN should place a high level of importance on the unity of country members, and have a mutual economic management mechanism in order to develop an economic integration as a common currency area in the future.