The purpose of this study was to clarify how the science teaching materials were compiled for the lower grades of elementary school in Hokkaido and Aichi prefecture in postwar Japan. Through the study of documentary records, the following results were reached: (1) As Hokkaido District Committee on Science Curriculum edited the units of the substitute science textbooks, "My observation from the 1st grade to the 3rd grade" (1950), it selected not only the units of "Observation of nature" (1941･42) but also the new ones. The selection of new units was based on "Course of study-science" (1947) and "Objectives of understandings" (1947) compiled by Advisory Committee on Science Curriculum. (2) In Hokkaido, also Hokkaido Science Education Association published the substitute science textbooks for the lower grades of elementary school. There were teaching materials conformed with the local conditions of Hokkaido's climate in that book for the 3rd grade. (3) According to the science teacher's guides from the 1st grade to the 3rd grade compiled by Aichi Prefecture Committee on Science Curriculum, there were so unique units including the two types for the rural area and the urban area, and the topic, "Making a popsicle", etc.