The purpose of this study was to make clear how the substitute science textbooks compiled by Kanto District Science Committee, "Kansatsu-to-kiroku (Observation and record)" (1948), were influenced by "Shizen-no-kansatsu (Observation of nature)" (1941・42) and affected on the authorized science textbooks, "Shin-tanoshii-kagaku (New pleasant science)" (1951). Through the study of documentary records, the following results were reached: (1) The units of the substitute science textbooks accounted for 30～60 percent of the sum total of the units of "Shizen-no-kansatsu". When the substitute science textbooks were compiled by above committee, these textbooks were not inherited from "Shizen-no-kansatsu" and were plotted with the new contents. (2) The units of the authorized science textbooks accounted for 10～20 percent of the sum total of the units of the substitute science textbooks. "Rika-shido-kenkyukai (Study group of teaching science)" compiled new units on the basis of the standard for science in elementary school. (3) In Postwar Japan, the compilation of these textbooks needed not only enthusiastic teachers participated in local district science committees, but also publication of "Rikai-no-mokuhyo (Object of understanding)" as a guideline for the new science textbook.