Abstract
The purpose of the study is to compare elementary school science textbooks ($3^{rd}$ grade) in Korea and the U.S., centering on the ways to present scientific concepts and inquiry process in the units of 'matter.' The analysis is focused on: a) general structure of the units; b) how to present scientific concepts in terms of its connections and complexity; c) how to present inquiry process in terms of its types and skills. The findings of the study are as follows. First, the contents of 'matter' units are scientific discipline-based in both countries. The general structure of the units in Korean textbooks is unrestricted compared to those in the U.S. Second, the connections among the concepts are poor and the level of complexity is low in Korean textbooks, which are contrary to those in the U.S. textbooks. Third, it is a common feature that the inquiry process is based on learners' everyday experiences with simple experiments in two countries' textbooks. However, the inquiry process in the U.S. textbooks is provided with detailed instructions while the process in Korea is presented with diverse activities without formal guidelines. Based on the results, the study suggests three recommendations to improve Korean textbooks: a) science contents should be linked to other disciplines in order to promote practical applications; b) scientific concepts are required to be tightly connected and provided with in-depth explanations; c) inquiry process is needed to be presented with specific guidance to facilitate scientific thinking.