This study intends to analyze if customers behave differently before and during the Chinese New Year holiday from the transactions data of a supermarket in Taiwan. The results show that customers visit the supermarket the most frequently during the Chinese New Year holiday followed by the preparation for the Chinese New Year holiday. On the other hand, customers who shop on the preparation for the Chinese New Year holiday have the highest total amount spent in average statistically. Vegetables and fruits, hot pot ingredients, cooked food, seafood, and tobacco, alcohol, and tea are the most purchased merchandize items in terms of money spent before the Chinese New Year holiday. The supermarket management can focus on the most frequently purchased and money spent merchandize items in order to meet customer needs.