ENThe paper reports the comparison of Lithuanian, Latvian and Russian Natural Science textbooks for primary school. The textbooks are compared in quantitative and qualitative aspects. Conclusions: the thematic structure of Natural Science textbooks for primary school in Lithuania, Latvia and Russia is different; in Latvian Natural Science textbooks for 1-4th grades there are 212 themes, in Lithuanian textbooks - 421, in Russian textbooks - 181; the Natural Science content of Lithuanian textbooks is integrated with social education; in Latvian textbooks there are more themes about the civilization of the country, but almost no historical themes; the teaching materials of Lithuanian, Latvian and Russian Natural Science textbooks differ from the point of view of Natural Sciences and socio-cultural questions; the biodiversity is broadly presented in Lithuanian textbooks in comparison with the Latvian textbooks. Key words: primary school, textbooks, natural science, biodiversity.