Young children often struggle with reasoning based on abstract relations, which is crucial for learning and thinking. Research has shown that children's relational reasoning abilities can be enhanced under certain circumstances. The underlying reasons and mechanisms behind such enhancement, however, remain unclear. This study examined the effectiveness of explanation, a recently discovered method, in enhancing children's relational reasoning abilities. Seventy-one 4- and 5-year-old children participated in a modified Relational Match to Sample (RMTS) task. Some children interacted with an experimenter who demonstrated relational matches and engaged in question-answer sessions, while others completed the task without such interactions. Results indicated that children who observed demonstrations and provided explanations or reports showed a higher proportion of relational matches compared to those who completed the task without such interactions. Furthermore, explanation was more effective than report in promoting children's relational reasoning. These findings suggest that interactive experiences that encourage exploration contribute to the development of children's relational reasoning abilities.