Science for the lower graders in the public elementary school has been established at Showa 16（1941）in Japan. But Seijo Elementary School has been founded at Taisho 6（1917）, when science for the lower graders has been established in this school. In this paper, the basis of establishment of science for the lower graders in Seijo Elementary School was analyzed, and then the following were made clear.
（1）The teachers in Seijo Elementary School believed'recapitulation theory', and they regarded the lower grades as the primitive times in the history of human progress.
Therefore, they thought that the lower groders had to study of nature.
（2）They thought that science（study of nature）was base for all subjects in school, especially language and arithmetic（or mathematics）.
（3）They thought that the lower graders liked science and could learn it.
（4）The then Japanese reader has contained scientific matters（natural things and phenomena）, too. But, they thought that science education was different in aim and method from reading education.
（5）They thought that establishment of science for the lower graders was essential to improvement of not only physical but spiritual life.