ABSTRACT The concept and methodology of price asymmetry analyses can be applied to the analysis of the regionalization of international crude oil markets. If markets are unified and properties of crude oils are similar, the price movements of crude oil in each market should be symmetric in the cases of price increases and decreases. Accordingly, in this study, the asymmetric movements of crude oil prices were analyzed to test the degree of market integration of the world crude oil markets using the asymmetric error correction model. As the results, the degrees of market integration were estimated differently in the cases of price increases and decreases.