This study performs an empirical study on how “Jeong (情)”, a feeling of affection or attachment in Korean, influences civil servants’ aggressive or friendly behavior toward customers. We divided the “Jeong” into three sub-dimensions: human tenderness, care of others and warm-heartedness. Based on the survey data, we analyzed the relational structure among the three measures and their impacts on the friendly/aggressive behavior toward customers. The results are as follows. First, human tenderness has a weak correlation with care of others and warm-heartedness. Second, the three sub-dimensions of “Jeong” have a different role in the friendly/aggressive behavior toward customers. For instance, human tenderness has a positive impact on friendly behavior and negative on aggressive one, while care of others has a contrasting impact on them. Warm-heartedness has no impact. Third, care of others has the largest impact on both behaviors among the three sub-dimensions.